Method and apparatus for resource-based csi acquisition in advanced wireless communication systems

ABSTRACT

A method of a user equipment (UE) in a wireless communication system is provided. The method comprises receiving, from at least one transmission and reception point (TRP) of a group of (N) TRPs, channel status information (CSI) configuration information, determining a CSI report based on the CSI configuration information, identifying, based on the configuration information, one or more TRPs of the group of (N) TRPs to transmit the determined CSI report, and transmitting, to the one or more TRPs, the determined CSI report over an uplink channel. The determined CSI report includes a TRP indicator for selecting (M) TRPs of the group of (N) TRPs, and CSI for each of the selected (M) TRPs, wherein N is greater than one, and wherein M is greater or equal to 1, and less or equal to N.

CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.17/301,029, filed on Mar. 22, 2021, which is a continuation of U.S.patent application Ser. No. 16/269,496, filed on Feb. 6, 2019, now U.S.Pat. No. 10,958,326, which claims priority to U.S. Provisional PatentApplication No. 62/710,427, filed on Feb. 16, 2018, U.S. ProvisionalPatent Application No. 62/713,261, filed on Aug. 1, 2018, and U.S.Provisional Patent Application No. 62/738,188, filed on Sep. 28, 2018.The content of the above-identified patent documents is incorporatedherein by reference.

TECHNICAL FIELD

The present disclosure relates generally to channel state acquisitionparticularly, relates to resource-based CSI acquisition in an advancedwireless communication system.

BACKGROUND

Understanding and correctly estimating the channel in an advancewireless communication system between a user equipment (UE) and an eNodeB (eNB) is important for efficient and effective wireless communication.In order to correctly estimate the channel conditions, the UE may report(e.g., feedback) information about channel measurement, e.g., CSI, tothe eNB. With this information about the channel, the eNB is able toselect appropriate communication parameters to efficiently andeffectively perform wireless data communication with the UE.

SUMMARY

Embodiments of the present disclosure provide methods and apparatusesfor wideband CSI reporting in an advanced wireless communication system.

In one embodiment, a UE in a wireless communication system is provided.The UE comprises a transceiver configured to receive, from at least onetransmission and reception point (TRP) of a group of (N) TRPs, channelstatus information (CSI) configuration information. The UE furthercomprises a processor operably connected to the transceiver, theprocessor configured to determine a CSI report based on the CSIconfiguration information, and identify, based on the configurationinformation, one or more TRPs of the group of (N) TRPs to transmit thedetermined CSI report. The transceiver is further configured totransmit, to the one or more TRPs, the determined CSI report over anuplink channel. The determined CSI report includes a TRP indicator forselecting (M) TRPs of the group of (N) TRPs, and CSI for each of theselected (M) TRPs. N is greater than one. M is greater or equal to 1,and less or equal to N.

In another embodiment, a TRP in a wireless communication system isprovided. The TRP comprises a transceiver configured to transmit, to aUE, CSI configuration information, wherein the TRP is at least one TRPof a group of (N) TRPs, and receive, from the UE, a CSI report over anuplink channel. The CSI report is determined based on the CSIconfiguration information. The determined CSI report includes a TRPindicator for selecting (M) TRPs of the group of (N) TRPs, and CSI foreach of the selected (M) TRPs. N is greater than one. M is greater orequal to 1, and less or equal to N.

In yet another embodiment, a method of a UE in a wireless communicationsystem is provided. The method comprises receiving, from at least oneTRP of a group of (N) TRPs, CSI configuration information, determining aCSI report based on the CSI configuration information, identifying,based on the configuration information, one or more TRPs of the group of(N) TRPs to transmit the determined CSI report, and transmitting, to theone or more TRPs, the determined CSI report over an uplink channel. Thedetermined CSI report includes a TRP indicator for selecting (M) TRPs ofthe group of (N) TRPs, and CSI for each of the selected (M) TRPs,wherein N is greater than one, and wherein M is greater or equal to 1,and less or equal to N.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure;

FIG. 2 illustrates an example eNB according to embodiments of thepresent disclosure;

FIG. 3 illustrates an example UE according to embodiments of the presentdisclosure;

FIG. 4A illustrates a high-level diagram of an orthogonal frequencydivision multiple access transmit path according to embodiments of thepresent disclosure;

FIG. 4B illustrates a high-level diagram of an orthogonal frequencydivision multiple access receive path according to embodiments of thepresent disclosure;

FIG. 5 illustrates a transmitter block diagram for a PDSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 6 illustrates a receiver block diagram for a PDSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 7 illustrates a transmitter block diagram for a PUSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 8 illustrates a receiver block diagram for a PUSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 9 illustrates an example multiplexing of two slices according toembodiments of the present disclosure;

FIG. 10 illustrates an example antenna blocks according to embodimentsof the present disclosure;

FIG. 11 illustrates an example network configuration according toembodiments of the present disclosure;

FIG. 12 illustrates a flow chart of a method for CSI acquisitionaccording to embodiments of the present disclosure; and

FIG. 13 illustrates a flow chart of another method for CSI acquisitionaccording to embodiments of the present disclosure.

DETAILED DESCRIPTION

FIGS. 1 through FIG. 13, discussed below, and the various embodimentsused to describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device.

The following documents and standards descriptions are herebyincorporated by reference into the present disclosure as if fully setforth herein: 3GPP TS 36.211 v14.4.0, “E-UTRA, Physical channels andmodulation;” 3GPP TS 36.212 v14.4.0, “E-UTRA, Multiplexing and Channelcoding;” 3GPP TS 36.213 v14.4.0, “E-UTRA, Physical Layer Procedures;”3GPP TS 36.321 v14.4.0, “E-UTRA, Medium Access Control (MAC) protocolspecification;” 3GPP TS 36.331 v14.4.0, “E-UTRA, Radio Resource Control(RRC) protocol specification;” 3GPP TR 22.891 v1.2.0; 3GPP TS 38.212v15.4.0, “E-UTRA, NR, Multiplexing and Channel coding;” and 3GPP TS38.214 v15.4.0, “E-UTRA, NR, Physical layer procedures for data.”

Aspects, features, and advantages of the disclosure are readily apparentfrom the following detailed description, simply by illustrating a numberof particular embodiments and implementations, including the best modecontemplated for carrying out the disclosure. The disclosure is alsocapable of other and different embodiments, and its several details canbe modified in various obvious respects, all without departing from thespirit and scope of the disclosure. Accordingly, the drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive. The disclosure is illustrated by way of example, and not byway of limitation, in the figures of the accompanying drawings.

In the following, for brevity, both FDD and TDD are considered as theduplex method for both DL and UL signaling.

Although exemplary descriptions and embodiments to follow assumeorthogonal frequency division multiplexing (OFDM) or orthogonalfrequency division multiple access (OFDMA), this disclosure can beextended to other OFDM-based transmission waveforms or multiple accessschemes such as filtered OFDM (F-OFDM).

The present disclosure covers several components which can be used inconjunction or in combination with one another, or can operate asstandalone schemes.

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a “beyond 4G network” or a“post LTE system.”

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission coverage, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques and the like arediscussed in 5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud radioaccess networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul communication, moving network,cooperative communication, coordinated multi-points (CoMP) transmissionand reception, interference mitigation and cancellation and the like.

In the 5G system, hybrid frequency shift keying and quadrature amplitudemodulation (FQAM) and sliding window superposition coding (SWSC) as anadaptive modulation and coding (AMC) technique, and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse codemultiple access (SCMA) as an advanced access technology have beendeveloped.

FIGS. 1-4B below describe various embodiments implemented in wirelesscommunications systems and with the use of orthogonal frequency divisionmultiplexing (OFDM) or orthogonal frequency division multiple access(OFDMA) communication techniques. The descriptions of FIGS. 1-3 are notmeant to imply physical or architectural limitations to the manner inwhich different embodiments may be implemented. Different embodiments ofthe present disclosure may be implemented in any suitably-arrangedcommunications system.

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure. The embodiment of the wireless network shownin FIG. 1 is for illustration only. Other embodiments of the wirelessnetwork 100 could be used without departing from the scope of thisdisclosure.

As shown in FIG. 1, the wireless network includes an eNB 101, an eNB102, and an eNB 103. The eNB 101 communicates with the eNB 102 and theeNB 103. The eNB 101 also communicates with at least one network 130,such as the Internet, a proprietary Internet Protocol (IP) network, orother data network.

The eNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe eNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business (SB); a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 116, which may be amobile device (M), such as a cell phone, a wireless laptop, a wirelessPDA, or the like. The eNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe eNB 103. The second plurality of UEs includes the UE 115 and the UE116. In some embodiments, one or more of the eNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, LTE,LTE-A, WiMAX, WiFi, or other wireless communication techniques.

Depending on the network type, the term “base station” or “BS” can referto any component (or collection of components) configured to providewireless access to a network, such as transmit point (TP),transmit-receive point (TRP), an enhanced base station (eNodeB or eNB),a 5G base station (gNB), a macrocell, a femtocell, a WiFi access point(AP), or other wirelessly enabled devices. Base stations may providewireless access in accordance with one or more wireless communicationprotocols, e.g., 5G 3GPP new radio interface/access (NR), long termevolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA),Wi-Fi 802.11a/b/g/n/ac, etc. For the sake of convenience, the terms “BS”and “TRP” are used interchangeably in this patent document to refer tonetwork infrastructure components that provide wireless access to remoteterminals. Also, depending on the network type, the term “userequipment” or “UE” can refer to any component such as “mobile station,”“subscriber station,” “remote terminal,” “wireless terminal,” “receivepoint,” or “user device.” For the sake of convenience, the terms “userequipment” and “UE” are used in this patent document to refer to remotewireless equipment that wirelessly accesses a BS, whether the UE is amobile device (such as a mobile telephone or smartphone) or is normallyconsidered a stationary device (such as a desktop computer or vendingmachine).

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with eNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the eNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, one or more of the UEs 111-116include circuitry, programing, or a combination thereof, for efficientresource-based CSI acquisition in an advanced wireless communicationsystem. In certain embodiments, and one or more of the eNBs 101-103includes circuitry, programing, or a combination thereof, forresource-based CSI acquisition in an advanced wireless communicationsystem.

Although FIG. 1 illustrates one example of a wireless network, variouschanges may be made to FIG. 1. For example, the wireless network couldinclude any number of eNBs and any number of UEs in any suitablearrangement. Also, the eNB 101 could communicate directly with anynumber of UEs and provide those UEs with wireless broadband access tothe network 130. Similarly, each eNB 102-103 could communicate directlywith the network 130 and provide UEs with direct wireless broadbandaccess to the network 130. Further, the eNBs 101, 102, and/or 103 couldprovide access to other or additional external networks, such asexternal telephone networks or other types of data networks.

FIG. 2 illustrates an example eNB 102 according to embodiments of thepresent disclosure. The embodiment of the eNB 102 illustrated in FIG. 2is for illustration only, and the eNBs 101 and 103 of FIG. 1 could havethe same or similar configuration. However, eNBs come in a wide varietyof configurations, and FIG. 2 does not limit the scope of thisdisclosure to any particular implementation of an eNB.

As shown in FIG. 2, the eNB 102 includes multiple antennas 205 a-205 n,multiple RF transceivers 210 a-210 n, transmit (TX) processing circuitry215, and receive (RX) processing circuitry 220. The eNB 102 alsoincludes a controller/processor 225, a memory 230, and a backhaul ornetwork interface 235.

The RF transceivers 210 a-210 n receive, from the antennas 205 a-205 n,incoming RF signals, such as signals transmitted by UEs in the network100. The RF transceivers 210 a-210 n down-convert the incoming RFsignals to generate IF or baseband signals. The IF or baseband signalsare sent to the RX processing circuitry 220, which generates processedbaseband signals by filtering, decoding, and/or digitizing the basebandor IF signals. The RX processing circuitry 220 transmits the processedbaseband signals to the controller/processor 225 for further processing.

The TX processing circuitry 215 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 225. The TX processing circuitry 215 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 210 a-210 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 215 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 205 a-205 n.

The controller/processor 225 can include one or more processors or otherprocessing devices that control the overall operation of the eNB 102.For example, the controller/processor 225 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 210 a-210 n, the RX processing circuitry 220, andthe TX processing circuitry 215 in accordance with well-knownprinciples. The controller/processor 225 could support additionalfunctions as well, such as more advanced wireless communicationfunctions.

For instance, the controller/processor 225 could support beam forming ordirectional routing operations in which outgoing signals from multipleantennas 205 a-205 n are weighted differently to effectively steer theoutgoing signals in a desired direction. Any of a wide variety of otherfunctions could be supported in the eNB 102 by the controller/processor225.

The controller/processor 225 is also capable of executing programs andother processes resident in the memory 230, such as an OS. Thecontroller/processor 225 can move data into or out of the memory 230 asrequired by an executing process.

The controller/processor 225 is also coupled to the backhaul or networkinterface 235. The backhaul or network interface 235 allows the eNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 235 could support communications overany suitable wired or wireless connection(s). For example, when the eNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 235 could allow the eNB102 to communicate with other eNBs over a wired or wireless backhaulconnection. When the eNB 102 is implemented as an access point, theinterface 235 could allow the eNB 102 to communicate over a wired orwireless local area network or over a wired or wireless connection to alarger network (such as the Internet). The interface 235 includes anysuitable structure supporting communications over a wired or wirelessconnection, such as an Ethernet or RF transceiver.

The memory 230 is coupled to the controller/processor 225. Part of thememory 230 could include a RAM, and another part of the memory 230 couldinclude a Flash memory or other ROM.

Although FIG. 2 illustrates one example of eNB 102, various changes maybe made to FIG. 2. For example, the eNB 102 could include any number ofeach component shown in FIG. 2. As a particular example, an access pointcould include a number of interfaces 235, and the controller/processor225 could support routing functions to route data between differentnetwork addresses. As another particular example, while shown asincluding a single instance of TX processing circuitry 215 and a singleinstance of RX processing circuitry 220, the eNB 102 could includemultiple instances of each (such as one per RF transceiver). Also,various components in FIG. 2 could be combined, further subdivided, oromitted and additional components could be added according to particularneeds.

FIG. 3 illustrates an example UE 116 according to embodiments of thepresent disclosure. The embodiment of the UE 116 illustrated in FIG. 3is for illustration only, and the UEs 111-115 of FIG. 1 could have thesame or similar configuration. However, UEs come in a wide variety ofconfigurations, and FIG. 3 does not limit the scope of this disclosureto any particular implementation of a UE.

As shown in FIG. 3, the UE 116 includes an antenna 305, a radiofrequency (RF) transceiver 310, TX processing circuitry 315, amicrophone 320, and receive (RX) processing circuitry 325. The UE 116also includes a speaker 330, a processor 340, an input/output (I/O)interface (IF) 345, a touchscreen 350, a display 355, and a memory 360.The memory 360 includes an operating system (OS) 361 and one or moreapplications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RFsignal transmitted by an eNB of the network 100. The RF transceiver 310down-converts the incoming RF signal to generate an intermediatefrequency (IF) or baseband signal. The IF or baseband signal is sent tothe RX processing circuitry 325, which generates a processed basebandsignal by filtering, decoding, and/or digitizing the baseband or IFsignal. The RX processing circuitry 325 transmits the processed basebandsignal to the speaker 330 (such as for voice data) or to the processor340 for further processing (such as for web browsing data).

The TX processing circuitry 315 receives analog or digital voice datafrom the microphone 320 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the processor 340.The TX processing circuitry 315 encodes, multiplexes, and/or digitizesthe outgoing baseband data to generate a processed baseband or IFsignal. The RF transceiver 310 receives the outgoing processed basebandor IF signal from the TX processing circuitry 315 and up-converts thebaseband or IF signal to an RF signal that is transmitted via theantenna 305.

The processor 340 can include one or more processors or other processingdevices and execute the OS 361 stored in the memory 360 in order tocontrol the overall operation of the UE 116. For example, the processor340 could control the reception of forward channel signals and thetransmission of reverse channel signals by the RF transceiver 310, theRX processing circuitry 325, and the TX processing circuitry 315 inaccordance with well-known principles. In some embodiments, theprocessor 340 includes at least one microprocessor or microcontroller.

The processor 340 is also capable of executing other processes andprograms resident in the memory 360, such as processes for CSI reportingon PUCCH. The processor 340 can move data into or out of the memory 360as required by an executing process. In some embodiments, the processor340 is configured to execute the applications 362 based on the OS 361 orin response to signals received from eNBs or an operator. The processor340 is also coupled to the I/O interface 345, which provides the UE 116with the ability to connect to other devices, such as laptop computersand handheld computers. The I/O interface 345 is the communication pathbetween these accessories and the processor 340.

The processor 340 is also coupled to the touchscreen 350 and the display355. The operator of the UE 116 can use the touchscreen 350 to enterdata into the UE 116. The display 355 may be a liquid crystal display,light emitting diode display, or other display capable of rendering textand/or at least limited graphics, such as from web sites.

The memory 360 is coupled to the processor 340. Part of the memory 360could include a random access memory (RAM), and another part of thememory 360 could include a Flash memory or other read-only memory (ROM).

Although FIG. 3 illustrates one example of UE 116, various changes maybe made to FIG. 3. For example, various components in FIG. 3 could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, theprocessor 340 could be divided into multiple processors, such as one ormore central processing units (CPUs) and one or more graphics processingunits (GPUs). Also, while FIG. 3 illustrates the UE 116 configured as amobile telephone or smartphone, UEs could be configured to operate asother types of mobile or stationary devices.

FIG. 4A is a high-level diagram of transmit path circuitry. For example,the transmit path circuitry may be used for an orthogonal frequencydivision multiple access (OFDMA) communication. FIG. 4B is a high-leveldiagram of receive path circuitry. For example, the receive pathcircuitry may be used for an orthogonal frequency division multipleaccess (OFDMA) communication. In FIGS. 4A and 4B, for downlinkcommunication, the transmit path circuitry may be implemented in a basestation (eNB) 102 or a relay station, and the receive path circuitry maybe implemented in a user equipment (e.g. user equipment 116 of FIG. 1).In other examples, for uplink communication, the receive path circuitry450 may be implemented in a base station (e.g. eNB 102 of FIG. 1) or arelay station, and the transmit path circuitry may be implemented in auser equipment (e.g. user equipment 116 of FIG. 1).

Transmit path circuitry comprises channel coding and modulation block405, serial-to-parallel (S-to-P) block 410, Size N Inverse Fast FourierTransform (IFFT) block 415, parallel-to-serial (P-to-S) block 420, addcyclic prefix block 425, and up-converter (UC) 430. Receive pathcircuitry 450 comprises down-converter (DC) 455, remove cyclic prefixblock 460, serial-to-parallel (S-to-P) block 465, Size N Fast FourierTransform (FFT) block 470, parallel-to-serial (P-to-S) block 475, andchannel decoding and demodulation block 480.

At least some of the components in FIGS. 4A 400 and 4B 450 may beimplemented in software, while other components may be implemented byconfigurable hardware or a mixture of software and configurablehardware. In particular, it is noted that the FFT blocks and the IFFTblocks described in this disclosure document may be implemented asconfigurable software algorithms, where the value of Size N may bemodified according to the implementation.

Furthermore, although this disclosure is directed to an embodiment thatimplements the Fast Fourier Transform and the Inverse Fast FourierTransform, this is by way of illustration only and may not be construedto limit the scope of the disclosure. It may be appreciated that in analternate embodiment of the present disclosure, the Fast FourierTransform functions and the Inverse Fast Fourier Transform functions mayeasily be replaced by discrete Fourier transform (DFT) functions andinverse discrete Fourier transform (IDFT) functions, respectively. Itmay be appreciated that for DFT and IDFT functions, the value of the Nvariable may be any integer number (i.e., 1, 4, 3, 4, etc.), while forFFT and IFFT functions, the value of the N variable may be any integernumber that is a power of two (i.e., 1, 2, 4, 8, 16, etc.).

In transmit path circuitry 400, channel coding and modulation block 405receives a set of information bits, applies coding (e.g., LDPC coding)and modulates (e.g., quadrature phase shift keying (QPSK) or quadratureamplitude modulation (QAM)) the input bits to produce a sequence offrequency-domain modulation symbols. Serial-to-parallel block 410converts (i.e., de-multiplexes) the serial modulated symbols to paralleldata to produce N parallel symbol streams where N is the IFFT/FFT sizeused in BS 102 and UE 116. Size N IFFT block 415 then performs an IFFToperation on the N parallel symbol streams to produce time-domain outputsignals. Parallel-to-serial block 420 converts (i.e., multiplexes) theparallel time-domain output symbols from Size N IFFT block 415 toproduce a serial time-domain signal. Add cyclic prefix block 425 theninserts a cyclic prefix to the time-domain signal. Finally, up-converter430 modulates (i.e., up-converts) the output of add cyclic prefix block425 to RF frequency for transmission via a wireless channel. The signalmay also be filtered at baseband before conversion to RF frequency.

The transmitted RF signal arrives at the UE 116 after passing throughthe wireless channel, and reverse operations to those at eNB 102 areperformed. Down-converter 455 down-converts the received signal tobaseband frequency, and remove cyclic prefix block 460 removes thecyclic prefix to produce the serial time-domain baseband signal.Serial-to-parallel block 465 converts the time-domain baseband signal toparallel time-domain signals. Size N FFT block 470 then performs an FFTalgorithm to produce N parallel frequency-domain signals.Parallel-to-serial block 475 converts the parallel frequency-domainsignals to a sequence of modulated data symbols. Channel decoding anddemodulation block 480 demodulates and then decodes the modulatedsymbols to recover the original input data stream.

Each of eNBs 101-103 may implement a transmit path that is analogous totransmitting in the downlink to user equipment 111-116 and may implementa receive path that is analogous to receiving in the uplink from userequipment 111-116. Similarly, each one of user equipment 111-116 mayimplement a transmit path corresponding to the architecture fortransmitting in the uplink to eNBs 101-103 and may implement a receivepath corresponding to the architecture for receiving in the downlinkfrom eNBs 101-103.

5G communication system use cases have been identified and described.Those use cases can be roughly categorized into three different groups.In one example, enhanced mobile broadband (eMBB) is determined to dowith high bits/sec requirement, with less stringent latency andreliability requirements. In another example, ultra reliable and lowlatency (URLL) is determined with less stringent bits/sec requirement.In yet another example, massive machine type communication (mMTC) isdetermined that a number of devices can be as many as 100,000 to 1million per km2, but the reliability/throughput/latency requirementcould be less stringent. This scenario may also involve power efficiencyrequirement as well, in that the battery consumption may be minimized aspossible.

A communication system includes a downlink (DL) that conveys signalsfrom transmission points such as base stations (BSs) or NodeBs to userequipments (UEs) and an Uplink (UL) that conveys signals from UEs toreception points such as NodeBs. A UE, also commonly referred to as aterminal or a mobile station, may be fixed or mobile and may be acellular phone, a personal computer device, or an automated device. AneNodeB, which is generally a fixed station, may also be referred to asan access point or other equivalent terminology. For LTE systems, aNodeB is often referred as an eNodeB.

In a communication system, such as LTE system, DL signals can includedata signals conveying information content, control signals conveying DLcontrol information (DCI), and reference signals (RS) that are alsoknown as pilot signals. An eNodeB transmits data information through aphysical DL shared channel (PDSCH). An eNodeB transmits DCI through aphysical DL control channel (PDCCH) or an Enhanced PDCCH (EPDCCH).

An eNodeB transmits acknowledgement information in response to datatransport block (TB) transmission from a UE in a physical hybrid ARQindicator channel (PHICH). An eNodeB transmits one or more of multipletypes of RS including a UE-common RS (CRS), a channel state informationRS (CSI-RS), or a demodulation RS (DMRS). A CRS is transmitted over a DLsystem bandwidth (BW) and can be used by UEs to obtain a channelestimate to demodulate data or control information or to performmeasurements. To reduce CRS overhead, an eNodeB may transmit a CSI-RSwith a smaller density in the time and/or frequency domain than a CRS.DMRS can be transmitted only in the BW of a respective PDSCH or EPDCCHand a UE can use the DMRS to demodulate data or control information in aPDSCH or an EPDCCH, respectively. A transmission time interval for DLchannels is referred to as a subframe and can have, for example,duration of 1 millisecond.

DL signals also include transmission of a logical channel that carriessystem control information. A BCCH is mapped to either a transportchannel referred to as a broadcast channel (BCH) when the DL signalsconvey a master information block (MIB) or to a DL shared channel(DL-SCH) when the DL signals convey a System Information Block (SIB).Most system information is included in different SIBs that aretransmitted using DL-SCH. A presence of system information on a DL-SCHin a subframe can be indicated by a transmission of a correspondingPDCCH conveying a codeword with a cyclic redundancy check (CRC)scrambled with system information RNTI (SI-RNTI). Alternatively,scheduling information for a SIB transmission can be provided in anearlier SIB and scheduling information for the first SIB (SIB-1) can beprovided by the MIB.

DL resource allocation is performed in a unit of subframe and a group ofphysical resource blocks (PRBs). A transmission BW includes frequencyresource units referred to as resource blocks (RBs). Each RB includesN_(sc) ^(RB) sub-carriers, or resource elements (REs), such as 12 REs. Aunit of one RB over one subframe is referred to as a PRB. A UE can beallocated M_(PDSCH) RBs for a total of M_(sc) ^(PDSCH)=M_(PDSCH)·N_(sc)^(RB) REs for the PDSCH transmission BW.

UL signals can include data signals conveying data information, controlsignals conveying UL control information (UCI), and UL RS. UL RSincludes DMRS and Sounding RS (SRS). A UE transmits DMRS only in a BW ofa respective PUSCH or PUCCH. An eNodeB can use a DMRS to demodulate datasignals or UCI signals. A UE transmits SRS to provide an eNodeB with anUL CSI. A UE transmits data information or UCI through a respectivephysical UL shared channel (PUSCH) or a Physical UL control channel(PUCCH). If a UE needs to transmit data information and UCI in a same ULsubframe, the UE may multiplex both in a PUSCH. UCI includes HybridAutomatic Repeat request acknowledgement (HARQ-ACK) information,indicating correct (ACK) or incorrect (NACK) detection for a data TB ina PDSCH or absence of a PDCCH detection (DTX), scheduling request (SR)indicating whether a UE has data in the UE's buffer, rank indicator(RI), and channel state information (CSI) enabling an eNodeB to performlink adaptation for PDSCH transmissions to a UE. HARQ-ACK information isalso transmitted by a UE in response to a detection of a PDCCH/EPDCCHindicating a release of semi-persistently scheduled PDSCH.

An UL subframe includes two slots. Each slot includes N_(symb) ^(UL)symbols for transmitting data information, UCI, DMRS, or SRS. Afrequency resource unit of an UL system BW is a RB. A UE is allocatedN_(RB) RBs for a total of N_(RB)·N_(sc) ^(RB) REs for a transmission BW.For a PUCCH, N_(RB)=1. A last subframe symbol can be used to multiplexSRS transmissions from one or more UEs. A number of subframe symbolsthat are available for data/UCI/DMRS transmission isN_(symb)=2·(N_(symb) ^(UL)−1)−N_(SRS), where N_(SRS)=1 if a lastsubframe symbol is used to transmit SRS and N_(SRS)=0 otherwise.

FIG. 5 illustrates a transmitter block diagram 500 for a PDSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the transmitter block diagram 500 illustrated in FIG. 5 isfor illustration only. FIG. 5 does not limit the scope of thisdisclosure to any particular implementation of the transmitter blockdiagram 500.

As shown in FIG. 5, information bits 510 are encoded by encoder 520,such as a turbo encoder, and modulated by modulator 530, for exampleusing quadrature phase shift keying (QPSK) modulation. A serial toparallel (S/P) converter 540 generates M modulation symbols that aresubsequently provided to a mapper 550 to be mapped to REs selected by atransmission BW selection unit 555 for an assigned PDSCH transmissionBW, unit 560 applies an Inverse fast Fourier transform (IFFT), theoutput is then serialized by a parallel to serial (P/S) converter 570 tocreate a time domain signal, filtering is applied by filter 580, and asignal transmitted 590. Additional functionalities, such as datascrambling, cyclic prefix insertion, time windowing, interleaving, andothers are well known in the art and are not shown for brevity.

FIG. 6 illustrates a receiver block diagram 600 for a PDSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the diagram 600 illustrated in FIG. 6 is for illustrationonly. FIG. 6 does not limit the scope of this disclosure to anyparticular implementation of the diagram 600.

As shown in FIG. 6, a received signal 610 is filtered by filter 620, REs630 for an assigned reception BW are selected by BW selector 635, unit640 applies a fast Fourier transform (FFT), and an output is serializedby a parallel-to-serial converter 650. Subsequently, a demodulator 660coherently demodulates data symbols by applying a channel estimateobtained from a DMRS or a CRS (not shown), and a decoder 670, such as aturbo decoder, decodes the demodulated data to provide an estimate ofthe information data bits 680. Additional functionalities such astime-windowing, cyclic prefix removal, de-scrambling, channelestimation, and de-interleaving are not shown for brevity.

FIG. 7 illustrates a transmitter block diagram 700 for a PUSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the block diagram 700 illustrated in FIG. 7 is forillustration only. FIG. 7 does not limit the scope of this disclosure toany particular implementation of the block diagram 700.

As shown in FIG. 7, information data bits 710 are encoded by encoder720, such as a turbo encoder, and modulated by modulator 730. A discreteFourier transform (DFT) unit 740 applies a DFT on the modulated databits, REs 750 corresponding to an assigned PUSCH transmission BW areselected by transmission BW selection unit 755, unit 760 applies an IFFTand, after a cyclic prefix insertion (not shown), filtering is appliedby filter 770 and a signal transmitted 780.

FIG. 8 illustrates a receiver block diagram 800 for a PUSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the block diagram 800 illustrated in FIG. 8 is forillustration only. FIG. 8 does not limit the scope of this disclosure toany particular implementation of the block diagram 800.

As shown in FIG. 8, a received signal 810 is filtered by filter 820.Subsequently, after a cyclic prefix is removed (not shown), unit 830applies a FFT, REs 840 corresponding to an assigned PUSCH reception BWare selected by a reception BW selector 845, unit 850 applies an inverseDFT (IDFT), a demodulator 860 coherently demodulates data symbols byapplying a channel estimate obtained from a DMRS (not shown), a decoder870, such as a turbo decoder, decodes the demodulated data to provide anestimate of the information data bits 880.

In next generation cellular systems, various use cases are envisionedbeyond the capabilities of LTE system. Termed 5G or the fifth generationcellular system, a system capable of operating at sub-6GHz and above-6GHz (for example, in mmWave regime) becomes one of the requirements. In3GPP TR 22.891, 74 5G use cases has been identified and described; thoseuse cases can be roughly categorized into three different groups. Afirst group is termed “enhanced mobile broadband (eMBB),” targeted tohigh data rate services with less stringent latency and reliabilityrequirements. A second group is termed “ultra-reliable and low latency(URLL)” targeted for applications with less stringent data raterequirements, but less tolerant to latency. A third group is termed“massive MTC (mMTC)” targeted for large number of low-power deviceconnections such as 1 million per km² with less stringent thereliability, data rate, and latency requirements.

In order for the 5G network to support such diverse services withdifferent quality of services (QoS), one method has been identified in3GPP specification, called network slicing. To utilize PHY resourcesefficiently and multiplex various slices (with different resourceallocation schemes, numerologies, and scheduling strategies) in DL-SCH,a flexible and self-contained frame or subframe design is utilized.

FIG. 9 illustrates an example multiplexing of two slices 900 accordingto embodiments of the present disclosure. The embodiment of themultiplexing of two slices 900 illustrated in FIG. 9 is for illustrationonly. FIG. 9 does not limit the scope of this disclosure to anyparticular implementation of the multiplexing of two slices 900.

Two exemplary instances of multiplexing two slices within a commonsubframe or frame are depicted in FIG. 9. In these exemplaryembodiments, a slice can be composed of one or two transmissioninstances where one transmission instance includes a control (CTRL)component (e.g., 920 a, 960 a, 960 b, 920 b, or 960 c) and a datacomponent (e.g., 930 a, 970 a, 970 b, 930 b, or 970 c). In embodiment910, the two slices are multiplexed in frequency domain whereas inembodiment 950, the two slices are multiplexed in time domain. These twoslices can be transmitted with different sets of numerology.

3GPP specification supports up to 32 CSI-RS antenna ports which enablean eNB to be equipped with a large number of antenna elements (such as64 or 128). In this case, a plurality of antenna elements is mapped ontoone CSI-RS port. For next generation cellular systems such as 5G, themaximum number of CSI-RS ports can either remain the same or increase.

FIG. 10 illustrates an example antenna blocks 1000 according toembodiments of the present disclosure. The embodiment of the antennablocks 1000 illustrated in FIG. 10 is for illustration only. FIG. 10does not limit the scope of this disclosure to any particularimplementation of the antenna blocks 1000.

For mmWave bands, although the number of antenna elements can be largerfor a given form factor, the number of CSI-RS ports—which can correspondto the number of digitally precoded ports—tends to be limited due tohardware constraints (such as the feasibility to install a large numberof ADCs/DACs at mmWave frequencies) as illustrated in FIG. 10. In thiscase, one CSI-RS port is mapped onto a large number of antenna elementswhich can be controlled by a bank of analog phase shifters. One CSI-RSport can then correspond to one sub-array which produces a narrow analogbeam through analog beamforming. This analog beam can be configured tosweep across a wider range of angles by varying the phase shifter bankacross symbols or subframes. The number of sub-arrays (equal to thenumber of RF chains) is the same as the number of CSI-RS portsN_(CSI-PORT). A digital beamforming unit performs a linear combinationacross N_(CSI-PORT) analog beams to further increase precoding gain.While analog beams are wideband (hence not frequency-selective), digitalprecoding can be varied across frequency sub-bands or resource blocks.

FIG. 11 illustrates an example network configuration 1100 according toembodiments of the present disclosure. The embodiment of the networkconfiguration 1100 illustrated in FIG. 11 is for illustration only. FIG.11 does not limit the scope of this disclosure to any particularimplementation of the configuration 1100.

In order for the 5G network to support such diverse services withdifferent quality of services (QoS), one scheme has been identified in3GPP specification, called network slicing.

As shown in FIG. 11, An operator's network 1110 includes a number ofradio access network(s) 1120 (RAN(s)) that are associated with networkdevices such as eNBs 1130 a and 1130 b, small cell base stations(femto/pico eNBs or Wi-Fi access points) 1135 a and 1135 b. The network1110 can support various services, each represented as a slice.

In the example, an URLL slice 1140 a serves UEs requiring URLL servicessuch as cars 1145 b, trucks 1145 c, smart watches 1145 a, and smartglasses 1145 d. Two mMTC slices 1150 a and 550 b serve UEs requiringmMTC services such as power meters 555 b, and temperature control box1155 b. One eMBB slice 1160 a serves UEs requiring eMBB services such ascells phones 1165 a, laptops 1165 b, and tablets 1165 c. A deviceconfigured with two slices can also be envisioned.

From 3GPP specification, MIMO has been identified as an essentialfeature in order to achieve high system throughput requirements and MIMOmay continue to be the same in NR. One of the key components of a MIMOtransmission scheme is the accurate CSI acquisition at the eNB (or TRP).For MU-MIMO, in particular, the availability of accurate CSI isnecessary in order to guarantee high MU performance. For TDD systems,the CSI can be acquired using the SRS transmission relying on thechannel reciprocity.

For FDD systems, on the other hand, it can be acquired using the CSI-RStransmission from eNB, and CSI acquisition and feedback from UE. In FDDsystems, the CSI feedback framework is “implicit” in the form ofCQI/PMI/RI derived from a codebook assuming SU transmission from eNB.

For 5G or NR systems, the above-mentioned CSI reporting paradigm fromLTE is also supported and referred to as Type I CSI reporting. Inaddition to Type I, a high-resolution CSI reporting, referred to as TypeII CSI reporting, is also supported to provide more accurate CSIinformation to gNB for use cases such as high-order MU-MIMO. In general,the Type I or Type II CSI reported using a PMI codebook, where the PMIhas two components, the first PMI i1 and the second PMI i2. If thesubband CSI reporting is configured, then the UE reports a singlewideband first PMI i1 which indicates a group of beams/pre-coders, andone second PMI i2 for each subband which indicates a precoder belongingto the group of precoders indicated by the reported first PMI i1. Thesubband CSI reporting is generally configured for use cases such asMU-MIMO transmission since the precoding is known to befrequency-selective (i.e., varies from one subband to another subband).The system performance depends on the PMI codebook. For example, the PMIcodebook for Type I CSI reporting performs worse than that for Type IICSI reporting, but the performance is proportional to the size of thePMI codebook which determines the CSI reporting payload (number offeedback bits). In fact, the Type I CSI reporting payload is muchsmaller than the Type II CSI reporting payload. So, the systemperformance gain is directly proportional to the PMI codebook and henceto the CSI reporting payload.

The above-mentioned dependence on the PMI codebook can be replaced orweakened if the gNB or network has some rough a priori information aboutthe subspace of the DL channel (e.g. a subset of the PMI codebook). Forexample, the gNB can beamform multiple CSI-RS resources, each with 1port, using a few candidate beamforming vectors, and the UE can report(select) one of these resources in each subband (e.g. via CRI) in orderto report subband CSI. With this approach, the gNB has the flexibilityto choose any candidate beamforming vectors, i.e., the reliance on PMIcodebook to report subband CSI is not needed. Note also that thisapproach is also applicable to UL MIMO wherein the UE beamforms multipleSRS resources, each with 1 port, using a few candidate beamformingvectors, and the gNB can report (indicate) one of these resources ineach subband (e.g. via SRI) in order to report subband CSI for UL. Thisdisclosure proposes the details of such CSI reporting methods.

Throughout the present disclosure, a CSI-RS resource refers to anon-zero power (NZP) CSI-RS resource, unless stated otherwise.

The higher layer parameter ReportFreqConfiguration indicates thefrequency granularity of a CSI Report. A CSI reporting settingconfiguration defines a CSI reporting band as a subset of subbands ofthe bandwidth part, where the ReportFreqConfiguration indicates singleCQI or multiple CQI reporting, as configured by the higher layerparameter CQI-FormatIndicator.

When single CQI reporting is configured, a single CQI is reported foreach codeword for the entire CSI reporting band. When multiple CQIreporting is configured, one CQI for each codeword is reported for eachsubband in the CSI reporting band.

In one embodiment 1, when the UE is configured with the higher layerparameter ReportQuantity set to “CRI/CQI,” then the UE may report asingle or multiple “CRI/CQI” according to at least one of the followingalternatives.

In one embodiment of Alt 1-1, if the higher layer parameterCQI-FormatIndicator indicates a single CQI reporting, then a single CRIand a single CQI are reported for each codeword for the entire CSIreporting band.

In one embodiment of Alt 1-2, if the higher layer parameterCQI-FormatIndicator indicates multiple CQI reporting, then one CQI foreach codeword is reported for each subband in the CSI reporting band. Inaddition, a single CRI is reported for each codeword for the entire CSIreporting band.

In one embodiment of Alt 1-3, if the higher layer parameterCQI-FormatIndicator indicates multiple CQI reporting, then one CQI foreach codeword is reported for each subband in the CSI reporting band. Inaddition, one CRI for each codeword is reported for each subband in theCSI reporting band.

In one embodiment of Alt 1-4, if the higher layer parameterCQI-FormatIndicator indicates a single CQI reporting and the higherlayer parameter CRI-FormatIndicator indicates a single CRI reporting,then a single CRI and a single CQI are reported for each codeword forthe entire CSI reporting band.

In one embodiment of Alt 1-5, if the higher layer parameterCQI-FormatIndicator indicates a single CQI reporting and the higherlayer parameter CRI-FormatIndicator indicates multiple CRI reporting,then a single CQI is reported for each codeword for the entire CSIreporting band and one CRI for each codeword is reported for eachsubband in the CSI reporting band.

In one embodiment of Alt 1-6, if the higher layer parameterCQI-FormatIndicator indicates multiple CQI reporting and the higherlayer parameter CRI-FormatIndicator indicates a single CRI reporting,then one CQI for each codeword is reported for each subband in the CSIreporting band and a single CRI is reported for each codeword for theentire CSI reporting band.

In one embodiment of Alt 1-7, if the higher layer parameterCQI-FormatIndicator indicates multiple CQI reporting and the higherlayer parameter CRI-FormatIndicator indicates multiple CRI reporting,then one CQI for each codeword is reported for each subband in the CSIreporting band and one CRI for each codeword is reported for eachsubband in the CSI reporting band.

Note that at least one of these alternatives (e.g., the aforementionedembodiments of Alt 1-1 to Alt 1-7) is configured via higher layersignaling (RRC). For example, the signaling can be via the parameterCQI-FormatIndicator or the parameter pair (CQI-FormatIndicator,CRI-FormatIndicator).

In a variation, the frequency granularity to report multiple CRIs in theaforementioned Alt 1-1 through Alt 1-7 is according to at least one ofthe following alternatives: Alt 1-8: the frequency granularity is equalto the subband size; Alt 1-9: the frequency granularity is smaller thanthe subband size, for example, equal to an RB; Alt 1-10: the frequencygranularity is larger than the subband size, for example, a multiple ofsubband size; and Alt 1-11: the frequency granularity is a fixedfraction (1/r) of the entire CSI reporting band, for example, ½ or ¼ or⅛. One of these alternatives is either fixed (e.g. Alt 1-8) orconfigured (e.g. via higher layer RRC signaling) or reported by the UE.

In another variation, the frequency granularity to report multiple CQIsin the aforementioned embodiments of Alt 1-1 through Alt 1-7 isaccording to at least one of the following alternatives: Alt 1-12: thefrequency granularity is equal to the subband size; and Alt 1-13: thefrequency granularity is equal to that to report CRI. One of thesealternatives is either fixed (e.g. the aforementioned embodiment of Alt1-12) or configured (e.g. via higher layer RRC signaling) or reported bythe UE.

In another variation, the parameter CRI-FormatIndicator is replaced withthe parameter PMI-FormatIndicator in the above alternatives.

In one embodiment 1A, the reported CRI (or CRIs) indicates a CSI-RSresource (or indicate CRI-RS resources) associated with a small numberof CSI-RS ports (e.g. 1 or 2). The UE is configured with N_(CSI-RS)≥1CSI-RS resources via higher layer signaling. Note that whenN_(CSI-RS)=1, then CRI does not need to be reported. In one method,N_(CSI-RS)>1 when ReportQuantity is set to “CRI/CQI.” In another method,N_(CSI-RS)≥1 when ReportQuantity is set to “CRI/CQI.” One of the twomethods may be supported in the specification.

In one embodiment 1B, the reported CQI (or CQIs) corresponds to a rankvalue that is equal to the number of ports associated with the CSI-RSresource indicated by the reported CRI (or correspond to rank valueseach of which is equal to the number of ports associated with the CSI-RSresource indicated by the corresponding reported CRI).

In one embodiment 1C, the number of ports associated with each of theN_(CSI-RS) CSI-RS resources is according to at least one of thefollowing alternatives. In one embodiment of Alt 1C-1, the number ofports is the same for all N_(CSI-RS) resources. Therefore, the reportedCQI (or CQIs) corresponds to a fixed rank that does not change acrossSBs, i.e., rank assumption for CQI reporting is WB. In one embodiment ofAlt 1C-2, the number of ports can be different from one resource toanother. Therefore, if multiple CQI and multiple CRI are reported, thenthe rank assumption for CQI reporting can change from SB to another. Forexample, CQI in one SB can correspond to rank 1 (if the correspondingreported CRI indicates a 1-port resource) and CQI and another SB cancorrespond to rank 2 (if the corresponding reported CRI indicates a2-port resource).

One use case of multiple CRI/CQI reporting is the case in which theprecoding or beamforming of data is in at least one of two domains: (1)radio frequency (RF) or analog domain and (2) digital or basebanddomain. The N_(CSI-RS) CSI-RS resources can be beamformed usingN_(CSI-RS) beamforming vectors. These beamforming vectors can beobtained by the gNB by measuring SRS transmitted by the UE (relying onUL-DL reciprocity). An example of such a system is high frequency (suchas millimeter wave) system.

Another use case is hybrid CSI in which the UE is configured to reportthe following two CSI reports. The first CSI report includes a long termand WB CSI indicating the information about a subspace or a set ofcandidate beamforming vectors. An example of subspace reporting is iionly reporting which indicates a set of DFT beams. The second CSIincludes the CRI/CQI as provided in this disclosure (embodiment 1 or 2or later embodiments). The CSI-RS resources for this second CSIreporting are beamformed or precoded using the subspace or the set ofcandidate beamforming vectors reported in the first CSI report.

Another user case is URLL applications in which CSI computation time canbe reduced significantly if only CRI/CQI needs to be reported sincethere is no need to perform codebook search for the PMI. So, the CSI canbe computed and reported much faster than the case (e.g. eMBBapplications) in which the UE needs to preform codebook search in orderto obtain the PMI for CSI reporting.

A few advantages/benefits of multiple CRI/CQI reporting (usingbeamformed CSI-RS) over CRI/PMI/CQI reporting (using non-precoded ornon-beamformed CSI-RS and PMI codebook) are as follows.

In one embodiment, the first advantage is in terms of performance gainwherein multiple CRI/CQI reporting is expected to show performance gainover CRI/PMI/CQI reporting. This is because of the fact that beamformedCSI-RS can achieve more SINR at the UE when compared with non-precodedCSI-RS.

The second advantage is that any beamforming or precoding vector can beused to beamform the CSI-RS resources. In particular, reliance on acodebook such as PMI codebook to beamform these resources is notnecessary.

The third advantage is that multiple CRI/CQI can reduce feedbackoverhead (bits) when compared with CRI/PMI/CQI reporting.

The fourth advantage is that the reliability can be improved (e.g. interms of lower BLER) and the PDSCH data transmission can be more robust(against interference, blockage etc.), which are required for URLLapplications.

In one embodiment 2, when the UE is configured with the higher layerparameter ReportQuantity set to “CRI/CQI” or “CRI/CQI/RI,” then the UEmay report a single or multiple “CRI/CQI” according to at least one ofthe alternatives in embodiment 1 (e.g., the aforementioned embodimentsof Alt 1-1 through Alt 1-7). In addition, the UE may report RI accordingto at least one of the following alternatives.

In one embodiment of Alt 2-1, RI is reported explicitly as a separateCSI component. In this alternative, the UE can be configured withReportQuantity set to “CRI/CQI/RI.” A few examples are as follows.

In one example 2-1, assuming each CSI-RS resource has only 1 port (i.e.,corresponds to a single transmission layer), if RI=1 is reported, thenone CRI is reported, and if RI=2 is reported, then two CRIs arereported, and so on. The reported CQI corresponds to the reported RIvalue and the aggregated reported CRI(s).

In one example 2-2, assuming each CSI-RS resource has only 2 ports(i.e., corresponds to two transmission layers and only even values of RIcan be reported), if RI=2 is reported, then one CRI is reported, and ifRI=4 is reported, then two CRIs are reported, and so on. The reportedCQI corresponds to the reported RI value and the aggregated reportedCRI(s).

In one example 2-3, assuming each CSI-RS resource has only 1 or 2 ports(i.e., corresponds to one of two transmission layers), if RI=1 isreported, then one CRI (associated with a 1 port resource) is reported,and if RI=2 is reported, then either one CRI (associated with a 2 portresource) is reported or two CRIs (each associated with a 1 portresource) are reported, and so on. The reported CQI corresponds to thereported RI value and the aggregated reported CRI(s).

In one embodiment Alt 2-2, RI is reported implicitly (jointly) eitherwith CRI or CQI. In this alternative, ReportQuantity can be set to“CRI/CQI.”

In one embodiment Alt 2-3, RI is not reported. In this alternative,ReportQuantity can be set to “CRI/CQI.”

Either one of the aforementioned embodiments of Alt 2-1, 2-2, and 2-3 isfixed in the specification (e.g., as a system parameter) or one of themis configured via higher layer (RRC) signaling. In this embodiment, RIcan be reported in a WB manner or in a per SB manner. The rest of thedetails of embodiment 1 are applicable to this embodiment also.

When the UE is configured to report CSI for each of multiple (N_(g))gNBs/TRPs (e.g. for non-coherent joint transmission from multiplegNBs/TRPs) and if the UE is further configured with a CSI-ReportConfigwith the higher layer parameter reportQuantity set to “cri-RI-CQI”,where the configuration is either joint for all TRPs or independent foreach TRP, then the UE may report CRI/RI/CQI for each gNB/TRP accordingto at least one of the following alternatives.

In one example of the embodiment Alt 2A-1, the UE is configured withhigher layer parameter non-PMI-PortIndication contained in aCSI-ReportConfig, where r ports are indicated in the order of layerordering for rank r and each CSI-RS resource in the CSI resource settingis linked to the CSI-ReportConfig based on the order of the associatedNZP-CSI-RS-ResourceId in the linked CSI resource setting for channelmeasurement given by higher layer parameterresourcesForChannelMeasurement. The higher layer parameternon-PMI-PortIndication contains (1) (2) (2) (3) (3) (3) (R) (R) (R) (v)(v) a sequence p₀ ^((I)),p₀ ⁽²⁾,p₁ ⁽²⁾,p₀ ⁽³⁾,p₁ ⁽³⁾,p₂ ⁽³⁾, . . . ,p₀^((R)),p₁ ^((R)), . . . , p_(R−1) ^((R)) of port indices, where P₀^((v)), . . . , p_(v−1) ^((v)) are the CSI-RS port indices associatedwith rank v and R∈{1,2, . . . , min(8, P)} where P∈{1,2,4,8} is thenumber of ports in the CSI-RS resource.

In one example of the embodiment Alt 2A-1, when calculating the CQI fora rank, the UE may use the ports indicated for that rank for theselected CSI-RS resource. The precoder for the indicated ports may beassumed to be the identity matrix. The configuration of different higherlayer parameters is either common for all TRPs or independent for eachTRP.

In one embodiment Alt 2A-2, the UE is configured to report CRI/RI/CQIper TRP, wherein one CRI is reported and RI reporting is according to atleast one of the following sub-alternatives.

In one embodiment Alt 2A-2-1, rank is a fixed value, for example to 1 orto a value configured via higher layer signaling, so RI is not reported,and in other words CRI/CQI is reported according to one of theembodiments of this disclosure.

In one embodiment Alt 2A-2-2, rank can take a value from multiplevalues, so RI is reported. Either CRI/CQI is reported where RI isreporting implicitly with CRI or/and CQI according to one of theembodiments of this disclosure, or CRI/RI/CQI is reported according toone of the embodiments of this disclosure.

If the number of ports in the CSI-RS resource indicated by the reportedCRI is more than one, then the precoder for CQI calculation can beeither fixed or higher layer configured or reported by the UE, where theprecoder can correspond to port selection with some scaling such as1/√{square root over (rank)}.

In one embodiment Alt 2A-3, the UE is configured to report CRI/RI/CQIper TRP, wherein multiple CRIs are reported and RI reporting isaccording to at least one of the following sub-alternatives.

In one embodiment Alt 2A-3-1, rank is a fixed value, for example to 1 orto a value configured via higher layer signaling, so RI is not reported,and in other words CRI/CQI is reported according to one of theembodiments of this disclosure.

In one embodiment Alt 2A-3-2, rank can take a value from multiplevalues, so RI is reported. Either CRI/CQI is reported where RI isreporting implicitly with CRI or/and CQI according to one of theembodiments of this disclosure, or CRI/RI/CQI is reported according toone of the embodiments of this disclosure.

If the number of ports in the CSI-RS resources indicated by the reportedCRIs is more than one, then the precoder for CQI calculation can beeither fixed or higher layer configured or reported by the UE, where theprecoder can correspond to port selection with some scaling such as1/√{square root over (rank)}.

The RI reporting (in Alt 2A-1/2A-2/2A-3) can also be according to atleast one of the following alternatives. In one embodiment Alt 2B-1,rank is fixed for each TRP, for example to rank 1, so RI is not reportedby any TRPs. In one embodiment Alt 2B-2, RI can be reported by each TRPand the reported rank>0. In one embodiment Alt 2B-3, RI can be reportedby each TRP and the reported rank can be 0 that indicates no CSIreporting or the respective TRP is not selected for CSI reporting. Inone example Ex 2B-1, the primary TRP (e.g. TRP #1) has rank>0, and thesecondary TRPs has rank>=0. In one example 2B-2: All TRPs have rank>=0.

In one example of Alt 2B-3, when number of TRPs is 2, the reported rankfor the primary TRP (e.g. TRP #1)≥the reported rank of the secondary TRP(e.g. TRP #2). Let (RI1, RI2) be the reported RI value pair for (TRP #1,TRP #2), and let RI be the overall rank or sum of the rank values acrossTRPs. Then, the rank distribution across TRPs is as follows: RI=1, (RI1,RI2)=(1,0); RI=2, (RI1, RI2)=(1,1) or (2,0); RI=3, (RI1, RI2)=(2,1) or(3,0); and RI=4, (RI1, RI2)=(2,2), (3,1), or (4,0).

In another example of Alt 2B-3, when number of TRPs is 2, the rankdistribution across TRPs is as follows: RI=1, (RI1, RI2)=(1,0), (0,1);RI=2, (RI1, RI2)=(1,1), (2,0), or (2,0); RI=3, (RI1, RI2)=(2,1), (3,0),(0,3), or (1,2); and RI=4, (RI1, RI2)=(2,2), (3,1), (4,0), (0,4), or(1,3).

The UE reports a joint RI or two separate RIs (RI1, RI2) eitherimplicitly with CRI or (CRI1, CRL2) or explicitly as separate CSIcomponent(s) RI or (RI1, RI2).

In one embodiment 3, which is a variation of embodiment 1 and 2, eachCSI-RS resource is configured with a fixed number (N) of ports. Forexample, N=1 or 2. Hence, the reported CQI corresponds to a rank value(RI) which is a multiple of N, i.e. the rank values belong to {N, 2N,3N, . . . }. The rank value (RI) may or may not reported. If RI isreported, then the RI is reported according to one of the examples inembodiment 2. Two examples are as follows. In one example 3-1, N=1 andthe possible number of layers (or rank values) belong to {1, 2, . . . }.In one example 3-2, N=2 and the possible number of layers (or rankvalues) belong to {2, 4, . . . }.

In one embodiment 4, when the UE is configured to report multipleCRI/CQI, then the UE reports multiple CRIs as explained in embodiment1-3 of the present disclosure except that the reported CRIs has adual-stage structure comprising two components: WB CRI component, asingle CRI indicating a group or subset of CSI-RS resources is reportedfor the entire CSI reporting band; and SB CRI component, one CRI isreported for each subband in the CSI reporting band, where the reportedCRI indicates a CRI-RS resource in the group or subset of CRI-RSresources indicated by the WB CRI component. This is similar to thedual-stage W1W2 PMI codebook to report a WB PMI (i1) and multiple SBPMIs (i2).

In one embodiment, a dual-stage CRI is reported only when the number ofports in each CSI-RS resources is large than a fixed value, e.g. 2 or 4.In another method, whether to report one CRI (single-stage) ordual-stage CRI is configured to the UE (e.g. via higher layer RRCsignaling).

In one example 4-1, the UE is configured with K_(s)>1 sets of CRI-RSresources, and the UE reports a WB CRI to indicate (select) one CSI-RSresource set (s) out of K_(s) CSI-RS resource sets, and also reports oneCRI for each SB to indicate (select) one CSI-RS resource out ofN_(CSI-RS,s) CSI-RS resources in the reported CSI-RS resource set (s).

In one example 4-2, the UE is configured with K_(s)=1 set of CRI-RSresources that are grouped (e.g. fixed grouping or sequentiallygrouping) into T groups. The UE reports a WB CRI to indicate (select)one CSI-RS resource group (t) out of T CSI-RS resource groups in theconfigured resource set, and also reports one CRI for each SB toindicate (select) one CSI-RS resource out of N_(CSI-RS,t) CSI-RSresources in the reported CSI-RS resource group (t).

In one example 4-3, the WB CRI indicates a subset (P) of gNB s/TRPs outof (Q) total gNBs/TRPs where P≤Q, and a SB CRI indicates a CSI-RSresource associated with the subset (P) gNBs/TRPs.

In one embodiment 5, the gNB transmits multiple ( N_(CSI-RS)>1) non-zeropower (NZP) CSI-RS resources, each associated with 1 port, where theseresources can be pre-coded/beamformed. The UE is configured to measurethe N_(CSI-RS) CSI-RS resources and report multiple WB CRIs. Thisconfiguration is via higher layer RRC signaling for example. The numberof reported WB CRIs corresponds to the reported RI. The multiple CRIsare reported according to one of the following alternatives.

In one embodiment Alt 5-1, the multiple CRIs are reported jointly. Atleast one of the following sub-alternatives is used.

In one embodiment Alt 5-1-1, RI is reported jointly (implicitly) withthe multiple CRIs, i.e. without any explicit reporting of RI value. Thenumber of bits to report multiple CRIs and RI jointly is

$\lceil {\log_{2}( {\sum\limits_{k = 1}^{\min{\{{L_{\max},N_{{CSI} - {RS}}}\}}}\begin{pmatrix}N_{{CSI} - {RS}} \\k\end{pmatrix}} )} \rceil,$

where L_(max) is the maximum number of supported layers for the PDSCH. Afew examples of joint CRI and RI indication for a few values of L_(max)are shown in TABLE 1 through TABLE 4.

In one embodiment Alt 5-1-2, RI is reported separately from the multipleCRIs. An example of separate CRI and RI indication is shown in Error!Reference source not found. Note that when N_(CSI-RS)=RI , there is noneed to indicate CRIs.

In another example, joint RI and CRI (e.g., the aforementionedembodiment Alt 5-1-1) are bit-map like signaling wherein lengthN_(CSI-RS) bitmap is used in indicate CRI(s) and RI jointly. Thereported RI corresponds to the number of “1”s in the bitmap and theCRI(s) correspond to the location of those “1”s. An example is shown inTABLE 6.

In one embodiment Alt 5-2, the multiple CRIs are reported separately. Atleast one of the following sub-alternatives is used. In one embodimentAlt 5-2-1, RI is reported jointly (implicitly) with the multiple CRIs,i.e. without any explicit reporting of RI value. In one embodiment Alt5-2-2, RI is reported separately from the multiple CRIs.

TABLE 1 Joint CRI/RI indication, L_(max) = 1 Bit field Bit field Bitfield mapped CRI(s), mapped CRI(s), mapped CRI(s), to index N_(CSI-RS) =2 to index N_(CSI-RS) = 3 to index N_(CSI-RS) = 4 0 0 0 0 0 0 1 1 1 1 11 2 2 2 2 3 reserved 3 3

TABLE 2 Joint CRI/RI indication, L_(max) = 2 Bit field Bit field Bitfield mapped CRI(s), mapped CRI(s), mapped CRI(s), to index N_(CSI-RS) =2 to index N_(CSI-RS) = 3 to index N_(CSI-RS) = 4 0 0 0 0 0 0 1 1 1 1 11 2 0, 1 2 2 2 2 3 reserved 3 0, 1 3 3 4 0, 2 4 0, 1 5 1, 2 5 0, 2 6-7reserved 6 0, 3 7 1, 2 8 1, 3 9 2, 3 10-15 reserved

TABLE 3 Joint CRI/RI indication, L_(max) = 3 Bit field Bit field Bitfield mapped CRI(s), mapped CRI(s), mapped CRI(s), to index N_(CSI-RS) =2 to index N_(CSI-RS) = 3 to index N_(CSI-RS) = 4 0 0 0 0 0 0 1 1 1 1 11 2 0, 1 2 2 2 2 3 reserved 3 0, 1 3 3 4 0, 2 4 0, 1 5 1, 2 5 0, 2 6 0,1, 2 6 0, 3 7 reserved 7 1, 2 8 1, 3 9 2, 3 10 0, 1, 2 11 0, 1, 3 12 0,2, 3 13 1, 2, 3 14-15 reserved

TABLE 4 Joint CRI/RI indication, L_(max) = 4 Bit field Bit field Bitfield mapped CRI(s), mapped CRI(s), mapped CRI(s), to index N_(CSI-RS) =2 to index N_(CSI-RS) = 3 to index N_(CSI-RS) = 4 0 0 0 0 0 0 1 1 1 1 11 2 0, 1 2 2 2 2 3 reserved 3 0, 1 3 3 4 0, 2 4 0, 1 5 1, 2 5 0, 2 6 0,1, 2 6 0, 3 7 reserved 7 1, 2 8 1, 3 9 2, 3 10 0, 1, 2 11 0, 1, 3 12 0,2, 3 13 1, 2, 3 14 0, 1, 2, 3 15 reserved

TABLE 5 Joint CRI and separate RI indication, L_(max) = 4 Bit fieldCRI(s), Bit field CRI(s), Bit field CRI(s), mapped N_(CSI-RS) = 2 mappedN_(CSI-RS) = 3 mapped N_(CSI-RS) = 4 to index RI = 1 RI = 2 to index RI= 1 RI = 2 RI = 3 to index RI = 1 RI = 2 RI = 3 RI = 4 0 0 0 0 0, 1 0 00, 1 0, 1, 2 1 1 1 1 0, 2 1 1 0, 2 0, 1, 3 2 2 1, 2 2 2 0, 3 0, 2, 3 3reserved reserved 3 3 1, 2 1, 2, 3 4 1, 3 5 2, 3 6 reserved 7 reserved

TABLE 6 bitmap for joint CRI and RI indication, N_(CSI-RS) = 4 RI CRI(s)Bitmap RI CRI(s) Bitmap 1 0 0001 2 1, 3 1010 1 1 0010 2 2, 3 1100 1 20100 3 0, 1, 2 0111 1 3 1000 3 0, 1, 3 1011 2 0, 1 0011 3 0, 2, 3 1101 20, 2 0101 3 1, 2, 3 1110 2 0, 3 1001 4 0, 1, 2, 3 1111 2 1, 2 0110

In one embodiment 5A, the gNB transmits multiple (N_(CSI-RS)>1) non-zeropower (NZP) CSI-RS resources, each associated with 2 ports, where theseresources can be pre-coded/beamformed. The UE is configured to measurethe N_(CSI-RS) CSI-RS resources and report multiple WB CRIs. Thisconfiguration is via higher layer RRC signaling for example. The numberof reported WB CRIs corresponds to the reported RI which take evennumber values, i.e., {2, 4, . . . } , since each CSI-RS has 2 ports,hence indicates two layers. The multiple CRIs are reported according toone of the alternatives (or their simple extension) in theaforementioned embodiment 5. The extension of the alternatives isstraightforward for those skilled in the art.

In one embodiment 5B, the gNB transmits multiple (N_(CSI-RS>)1) non-zeropower (NZP) CSI-RS resources, each associated with 1 or 2 ports, wherethese resources can be pre-coded/beamformed. The UE is configured tomeasure the N_(CSI-RS) CSI-RS resources and report multiple WB CRIs.This configuration is via higher layer RRC signaling for example. Thereported RI value corresponds to the (total) sum of number of ports inthe reported CRIs, i.e., RI=Σ_(c∈S)N_(ports)(c), where S is the set ofreported CRIs, and N_(ports)(c) is the number of ports associated withthe CRI c in the set S. The multiple CRIs are reported according to oneof the alternatives (or their simple extension) in the aforementionedembodiment 5. The extension of the alternatives is straightforward forthose skilled in the art.

In one embodiment 5C, the maximum number of CRIs that can be reportedcorresponds to N=1, 2, 3, or 4 that is configured to report CRI/L1-RSRPor SSBRI/L1-RSRP, where N is higher layer configured.

In one embodiment 5D, instead of reporting multiple WB CRIs as explainedearlier in the present disclosure (e.g. in embodiment 5), the UE isconfigured to report a single WB CRI which indicates at least one of thefollowing.

In one embodiment Alt 5D-1, a group of CSI-RS resources where thegrouping is either fixed/pre-determined or higher layer configured. Inone embodiment Alt 5D-2, a group of CRIs where the grouping is eitherfixed/pre-determined or higher layer configured. In one embodiment Alt5D-3, a CSI-RS resource set out of multiple CSI-RS resource sets wherethe multiple CSI-RS resource sets are configured to the UE.

In one embodiment 5E, a UE is configured with the higher layer parameterCSIRS-SetUse of value “CodeBook” or “NonCodeBook.” When the UE isconfigured with CSIRS-SetUse=“NonCodeBook,” then the UE reports multipleWB CRIs as explained in some of the embodiments of present disclosure(e.g. the aforementioned embodiment 5). When the UE is configured withCSIRS-SetUse=“CodeBook.” then the UE reports SB CRIs as explained insome of the embodiments of present disclosure (e.g. embodiment 1).Alternatively, when the UE is configured with CSIRS-SetUse=“CodeBook.”then the UE reports at least one of “CRI/RI/CQI” or “LI/CRI/PMI/CQI/RI”or “CRI/PMI/CQI/RI” or “CRI/i1/CQI/RI” or “CRI/i1/RI.”

In one embodiment 5F, the UE is configured to report a single WB CRI foreach gNB/TRP out of multiple gNBs/TRPs, where the UE is configured toreport CSI including CRI (e.g. CRI/CQI) for multiple gNBs/TRPs.

In one embodiment 6, the UE is configured to measure N_(g)>1 sets ofCSI-RS resources for N_(g)>1 TRPs (or antenna panels): set S₁ comprisingN_(CSI-RS,1)≥1 CSI-RS resources for TRP #1; set S₂ comprisingN_(CSI-RS,2)≥1 CSI-RS resources for TRP #2; . . . set S_(N) _(g)comprising N_(CSI-RS,N) _(g) ≥1 CSI-RS resources from TRP #N_(g). Thisconfiguration is either via higher layer RRC signaling or more dynamicMAC CE based or DCI based signaling.

Alternatively, the N_(g)>1 sets comprise a single CSI-RS resource set.i.e., each of the N_(g) sets is equivalent to a subset of the singleCSI-RS resource set.

The resource for interference measurement for CQI calculation/reportingis according to at least one of the following alternatives.

In one embodiment Alt 6-1, the UE is not configured with any additionalresources for interference measurement, and the UE measures both channeland interference using the N_(g)>1 sets of CSI-RS resources.

In one embodiment Alt 6-2, the UE is configured with additionalresource(s) for interference measurement. At least one of the followingexample is used.

In one example Ex 6-1, the UE is configured with N_(g)>1 sets of CSI-RSresources for channel measurement and CSI-IM resource(s) forinterference measurement, where CSI-IM resource(s) is (are) configuredfor either all or a subset of the N_(g) TRPs.

In one example Ex 6-2, the UE is configured with N_(g)>1 sets of NZPCSI-RS resources for channel measurement and zero power (ZP) CSI-RSresource(s) for interference measurement, where ZP CSI-RS resource(s) is(are) configured for either all or a subset of the N_(g) TRPs.

In one example Ex 6-3, the UE is configured with N_(g)>1 sets of NZPCSI-RS resources for channel measurement and additional sets of NZPCSI-RS resource(s) for interference measurement, where the additionalsets of NZP CSI-RS resource(s) is (are) configured for either all or asubset of the N_(g) TRPs.

The UE is then configured to report multiple CRI/CQI (as providedearlier in the present disclosure) to at least one of the N_(g)>1 TRPs.As an example, the UE is configured to report multiple CRI/CQI (asprovided earlier in the present disclosure) for each of the N_(g)>1TRPs. This configuration is either via higher layer RRC signaling ormore dynamic MAC CE based or DCI based signaling.

At least one of the following alternatives is used to report N_(g) CSIreports.

In one embodiment Alt 6A-1, each of the N_(g) CSI reports is derivedusing the corresponding set of the CSI-RS resources (i.e. CSI-RSresource sets are one-to-one mapped to the CSI reports).

In one embodiment Alt 6A-2, at least one of the N_(g) CSI reports isderived using multiple sets of CSI-RS resources. For example, ifN_(g)=2, then the CSI report for TRP #1 can be derived using both sets(S₁ and S₂) of CSI-RS resources; and likewise, the CSI report for TRP #2can also be derived using both sets of CSI-RS resources. Such linking ofmultiple CSI-RS resource sets to derive a CSI report can beconfigurable, for example, via higher layer signaling or more dynamicMAC CE based or DCI based signaling.

When the UE is configured to report CSI for each of multiple (N_(g))gNBs/TRPs (e.g. for non-coherent joint transmission from multiplegNBs/TRPs), where the configuration is either joint for all TRPs orindependent for each TRP, then the UE may report a single joint CSIreport comprising CSI reports for all TRPs, for example, to the primaryTRP (or TRP #1). Or, the UE may report an independent CSI report foreach TRP, for example, to the respective TRP.

In one example of CSI report, the configuration includes the higherlayer parameter ReportQuantity set to “CRI/CQI,” and the UE may report asingle or multiple “CRI/CQI” according to at least one of alternativesprovided in this disclosure (e.g. the aforementioned one of embodimentsAlt 1-1 through Alt 1-7). In one example, a single joint CSI reportcomprising CRI/CQI for all TRPs is reported, for example, to the primaryTRP (or TRP #1). In another example, an independent CRI/CQI report foreach TRP is reported, for example, to the respective TRP.

In another example of CSI report, the configuration includes the higherlayer parameter ReportQuantity set to “CRI/L1-RSRP,” and the UE mayreport a single joint CSI report comprising CRI/L1-RSRP for all TRPs oran independent CRI/CQI report for each TRP.

The UCI carrying the CSI for multiple (N_(g)) gNBs/TRPs can be divided(partitioned) into two parts: part 1 and part 2, where UCI part 1carries a subset of the CSI reports for multiple gNBs/TRPs (i.e., CSIpart 1), and the UCI part 2 carries the remaining CSI reports formultiple gNBs/TRPs (i.e. CSI part 2). The CSI part 1 has fixed payload(number of bits) and the corresponding UCI part 1 is always reported.The CSI part 2 can have variable payload (number of bits) and thecorresponding UCI part 2 may or may not be reported. For example, UCIpart 2 is not reported if CSI part 2 has zero payload (i.e. notreported).

The information about the size of the CSI part 2 or UCI part 2 isincluded in the UCI or CSI part 1. In one example, the informationincludes a number (N) of TRPs (out of the total N_(g)) whose CSIs arereported in UCI part 2. In another example, the information includes anumber (N₂) of TRPs (out of the remaining N_(g)-N₁) whose CSIs arereported in UCI part 2, where N₁ and N₂ respectively are number of TRPswhose CSIs are included in UCI part 1 and part 2. In another example,the information includes a bitmap that indicates whether CSI for a TRPassociated with UCI part 2 is reported or not. The length of the bitmapcan be N₂. The information about the size of the CSI part 2 or UCI part2 can be explicit as a separate CSI component in CSI part 1 or implicitwith one of the CSI components in CSI part 1, for example with RI (ifreported) or with CRI.

UCI part 1 and UCI part 2 are reported according to at least one of thefollowing alternatives.

In one embodiment Alt 6B-1, UCI part 1 and UCI part 2 are reported tothe primary TRP (e.g. TRP #1) only, and not to other TRPs.

In one embodiment Alt 6B-2, UCI part 1 and UCI part 2 are reported tothe primary TRP (e.g. TRP #1) only, and UCI part 2 is reported to one ofthe remaining TRPs.

In one embodiment Alt 6B-3, UCI part 1 is reported to the primary TRP(e.g. TRP #1) only, and UCI part 2 is reported to one of the remainingTRPs.

In one example, UCI part 1 carries the CSI for the primary TRP (i.e. TRP#1), and also includes the information about the number (N₂≥0) of theremaining TRPs (e.g. TRP #i, where i>1) whose CSIs are reported usingUCI part 2. The UCI part 2 carries CSIs of the N₂ of the remaining TRPs(e.g. TRP #i, where i>1). Note that UCI part 2 payload varies (since N₂varies), in particular, UCI part 2 is not reported if N₂=0. If N_(g)>2and N_(g)−1>N₂ (i.e., number of remaining TRPs>number of TRPs whose CSIis reported via UCI part 2), then an indication is needed to indicatethe indices of the TRPs whose CSIs are reported.

In another example, UCI part 1 carries the CSI for the primary TRP (i.e.TRP #1), and also includes the information (e.g. a bitmap) about theindices of the TRPs whose CSIs are reported using UCI part 2. The UCIpart 2 carries CSIs of the N₂ of the remaining TRPs (e.g. TRP #i, wherei>1). Note that UCI part 2 payload varies (since N₂ varies), inparticular, UCI part 2 is not reported if N₂=0.

The reasons to support variable N₂ are as follows. In one example of thereasons, the first is the case in which the DL channel for some TRPs areso weak (when compared with other TRPs) that there is no benefit of datatransmission from such weak TRPs. This can happen due to blockage (e.g.in millimeter wave or FR2 communication) or strong interference. Inanother example of the reasons is the case in which a UE can't supportsimultaneous PDSCH reception from all configured (N_(g)) TRPs.

In a variation, the UCI carrying the CSI for multiple (N_(g)) gNBs/TRPscan be divided (partitioned) into N_(g) parts, where UCI part i carriesCSI part i corresponding to the CSI of the i-th gNB/TRP. The CSI part 1has fixed payload (number of bits) and the corresponding UCI part 1 isalways reported. The CSI part i (i>1) also has a fixed payload (numberof bits) but the CSI part i may or may not be reported. Thecorresponding UCI part i therefore has fixed payload if CSI part i isreported and CSI part i is not reported if CSI part i is not reported.

The information about the size of the CSI part i or UCI part i isincluded in the UCI or CSI part 1. In one example, the informationincludes a number (N) of TRPs (out of the total N_(g)) whose CSIs arereported in UCI part i (i>1). In another example, the informationincludes a number (N₂) of TRPs (out of the remaining N_(g)-N₁) whoseCSIs are reported in UCI part i (i>1), where N₁ and N₂ respectively arenumber of TRPs whose CSIs are included in UCI part 1 and UCI part i(i>1). In another example, the information includes a bitmap thatindicates whether CSI for a TRP associated with UCI part i (i>1) isreported or not. The length of the bitmap can be N₂.

UCI part 1 and UCI part i (i>1) are reported according to at least oneof the following alternatives. In one example Alt 6C-1, UCI part 1 andUCI part i (i>1) are reported to the primary TRP (e.g. TRP #1) only, andnot to other TRPs. In another example Alt 6C-2, UCI part 1 and UCI parti (i>1) are reported to the primary TRP (e.g. TRP #1) only, and UCI parti (i>1) is reported to the respective TRP i. In yet another example Alt6C-3, UCI part 1 is reported to the primary TRP (e.g. TRP #1) only, andUCI part i (i>1) is reported to one of the remaining TRP i.

In one embodiment 6A, the UE is configured to measure N_(g)>1 sets ofCSI-RS resources or N_(g)>1 TRPs (or antenna panels) as explained inembodiment 6 above, and the UE is further configured with the higherlayer parameter ReportQuantity set to “CRI/X” for CSI reporting, thenthe UE may report “CRI/X” as CSI report for each resource set (or TRP)as follows. The CSI report for each TRP comprises {CRI, X}, where CRIcan take zero value (i.e., CRI=0 indicating zero resource selection,i.e., CSI is not reported for that TRP). When CRI=0, X is not reported,i.e., only CRI is reported. Also, the UE may not report CRI=0 for allN_(g) TRPs. In other words, the UE may report {CRI, X} where CRI>0 forat least one TRP. Also, CRI can be reported independent per TRP or jointacross TRPs. The quantity X is either CQI or RI/CQI or RI/CQI/PMI orRI/CQI/PMI/LI.

When X=CQI, the overall RI (total number of layers across TRPs) is notreported, and equals number of resource(s) indicated via CRI(s) or sumof the number of ports associated with the resource(s) indicated viaCRI(s). An important use case for such non-PMI feedback for multi-TRP iswhen there are large number of TRPs, each with small number of ports(e.g. 1), which is relevant for FR2 and URLLC scenarios, potentiallywith channel reciprocity.

In one example, when X=CQI, CRI is reported in a WB manner and CQI isreported either WB or per SB (e.g. based on higher layer configuration).

In a variation of this embodiment, the UE can also be configured withN_(g)=1 set of CSI-RS resources for N_(g)=1 TRP (or antenna panel). Inanother variation of this embodiment, whether CRI can take zero value(i.e., CRI=0 indicating zero resource selection, i.e., CSI is notreported for that TRP) or CRI>0 is configured to the UE (e.g. via higherlayer RRC, or dynamic DCI based signalling). In another variation ofthis embodiment, whether CRI can take zero value (i.e., CRI=0 indicatingzero resource selection, i.e., CSI is not reported for that TRP) orCRI>0 is depends on the value of N_(g). For example, CRI can take zerovalue if N_(g)>0 and CRI>0 if N_(g)=1.

In one embodiment 6B, the UE is configured to measure N_(g)>1 sets ofCSI-RS resources or N_(g)>1 TRPs (or antenna panels) as explained inembodiment 6 above, and the UE is further configured with the higherlayer parameter ReportQuantity set to “RI/X” for CSI reporting, then theUE may report “RI/X” as CSI report for each resource set (or TRP) asfollows. The CSI report for each TRP comprises {RI, X}, where RI cantake zero value (i.e., RI=0 indicating CSI is not reported for thatTRP). When RI=0, X is not reported, i.e., only RI is reported. Also, aUE may not report RI=0 for all N_(g) TRPs. In other words, a UE mayreport {RI, X} where RI>0 for at least one TRP. Also, RI can be reportedindependent per TRP or joint across TRPs. The quantity X is either CQIor CRI/CQI or CRI/CQI/PMI or CRI/CQI/PMI/LI. The overall RI (totalnumber of layers across TRPs) equals sum of all RIs for all TRPs.

In one example, when X=CQI, RI is reported in a WB manner and CQI isreported either WB or per SB (e.g. based on higher layer configuration).

In a variation of this embodiment, the UE can also be configured withN_(g)=1 set of CSI-RS resources for N_(g)=1 TRP (or antenna panel). Inanother variation of this embodiment, whether RI can take zero value(i.e., RI=0 indicating CSI is not reported for that TRP) or RI>0 isconfigured to the UE (e.g. via higher layer RRC, or dynamic DCI basedsignalling). In another variation of this embodiment, whether RI cantake zero value (i.e., RI=0 indicating CSI is not reported for that TRP)or RI>0 is depends on the value of N_(g). For example, RI can take zerovalue if N_(g)>0 and RI>0 if N_(g)=1.

In one embodiment 6C, the UE is configured to measure N_(g)>1 sets ofCSI-RS resources or N_(g)>1 TRPs (or antenna panels) as explained inembodiment 6 above, and the UE is further configured with the higherlayer parameter ReportQuantity set to “CRI/RI/X” for CSI reporting, thenthe UE may report “CRI/RI/X” as CSI report for each resource set (orTRP) as follows. The CSI report for each TRP comprises {CRI, RI, X},where both CRI and RI can take zero value simultaneously (i.e., CRI=RI=0indicating zero resource selection, i.e., CSI is not reported for thatTRP) but only one of them can't be zero, i.e., (CRI, RI)=(0,1) or (1,0)can't be reported. In other words, (CRI, RI) is either (0, 0) or (a, b)where a>0 and b>0. When CRI=RI=0, X is not reported, i.e., only (CRI,RI)=(0,0) is reported. Also, a UE may not report CRI=RI=0 for all N_(g)TRPs.

In other words, a UE may report {CRI, RI, X} where RI>0 and CRI>0 for atleast one TRP. For each TRP, (CRI, RI) can be jointly encoded forreporting purpose. Or, CRI and RI are encoded separately. Also, (CRI,RI) can be reported independent per TRP or joint across TRPs. Thequantity X is either CQI or CQI/PMI or CQI/PMI/LI. When X=CQI, theoverall RI (total number of layers across TRPs) equals sum of all RIsfor all TRPs.

In one example, when X=CQI, CRI is reported in a WB manner and CQI isreported either WB or per SB (e.g. based on higher layer configuration).

In a variation of this embodiment, the UE can also be configured withN_(g)=1 set of CSI-RS resources for N_(g)=1 TRP (or antenna panel). Inanother variation of this embodiment, whether CRI and RI can take zerovalue (i.e., CRI=RI=0 indicating zero resource selection, i.e., CSI isnot reported for that TRP) or CRI, RI>0 is configured to the UE (e.g.via higher layer RRC, or dynamic DCI based signaling). In anothervariation of this embodiment, whether CRI and RI can take zero value(i.e., CRI=RI=0 indicating zero resource selection, i.e., CSI is notreported for that TRP) or CRI, RI>0 is depends on the value of N_(g).For example, CRI and RI can take zero value if N_(g)>0 and CRI, RI>0 ifN_(g)=1.

In one embodiment 7, the UE is configured to measure multiple CSI-RSresources (either in one CSI-RS resource set or in multiple CSI-RSresource sets), each with a fixed number of ports (e.g. 1 port), wherethese resources can be pre-coded/beamformed. The UE is configured toreport multiple CRIs (either alone or with CQI, i.e., CRI/CQI) accordingto at least one of the following alternatives (1 port CSI-RS resourcesare assumed in these alternatives for illustration only).

In one embodiment Alt 7-1, multiple N>1 CRIs, (CRI_(i),CRI₂, . . . ,CRI_(N)), are reported such that the multiple is considered only in thespatial domain (i.e., N CRIs correspond to N layers) and not in thefrequency domain (i.e., reported CRIs or layers are wideband). In otherwords, the reported N CRIs are WB, and the reported N CRIs indicate Nlayers.

In one example 7-1-1, N>1 CRIs indicate N>1 layers (1 CRI for eachlayer), where layers are formed using a single antenna panel (i.e. allantenna ports belong to a single antenna panel).

In one example 7-1-2: N>1 CRIs indicate N>1 layers (1 CRI for eachlayer), where N layers are formed using N antenna panels (or N TRPs). Inone alternative, N layers are one-to-one mapped to N antenna panels (orN TRPs). In another alternative, at least one of N layers maps tomultiple antenna panels (or TRPs). The number of reported CRIscorresponds to the reported RI. The RI may or may not reported withCRIs. The multiple CRIs are reported according to one of the followingalternatives in the aforementioned embodiment 5.

In one example Alt 7-2, multiple M>1 CRIs, (CR/₁, CRL₂, . . . ,CRI_(M)), are reported such that the multiple is not considered in thespatial domain (i.e., the number of layers is the same in all reportedCRIs) and is considered only in the frequency domain (i.e., M CRIscorrespond to M parts of the system bandwidth or CSI reportingbandwidth). In other words, 1 CRI is reported for each of the M parts ofthe system bandwidth or CSI reporting bandwidth.

In one example 7-2-1, M CRIs one-to-one correspond to M bandwidth parts(e.g. 2 CRIs are reported for 2 bandwidth parts where CRI to bandwidthpart mapping is one-to-one). In one example 7-2-2, M CRIs one-to-onecorrespond M SBs (e.g. CRI replaces SB PMI reporting).

In one example Alt 7-3, multiple NM>1 CRIs, (CRI_(1,1),CRI_(1,2), . . ., CRI_(1,N), CRI_(2,1), CRI_(2,2), . . . , CRI_(2,N), . . . , CRI_(M,1),CRI_(M,2), . . . , CRI_(M,N)), are reported such that the multiple isconsidered in both the spatial domain and the frequency domain. In otherwords, N CRIs are reported for each of the M parts of the systembandwidth or CSI reporting bandwidth, where N CRIs correspond to Nlayers.

In a variation, when the UE is configured to report CSI for multiple(N_(g)) gNBs/TRPs (e.g. for non-coherent joint transmission frommultiple gNBs/TRPs, and the UE is further configured to report multipleCRIs in spatial domain, then embodiment 7 (Alt 7-1, Alt 7-3) can beextended according to at least one of the following alternatives.

In one example Alt 7A-1, multiple CRIs are reported in spatial domain,where CRIs correspond to a single TRP. In one example Alt 7A-2, multipleCRIs are reported in spatial domain, where 1 CRI is reported for each ofthe multiple TRPs. In one example Alt 7A-3, multiple CRIs are reportedin spatial domain, where more than 1 CRIs can be reported for each ofthe multiple TRPs.

In one embodiment 8, a UE is configured with the higher layer parameterSRS-SetUse=“NonCodeBook,” then the UE is indicated with multiple SRIs(via UL-related DCI signaling) for UL MIMO transmission. The multipleSRIs are determined/indicated according to some of the embodiments ofpresent disclosure (e.g. the aforementioned embodiment 1-7) except thatCSI-RS and CRI are replaced with SRS and SRI respectively. For instance,the UE reports multiple SRIs according to at least one of the followingalternatives.

In one embodiment Alt 8-1, if the higher layer parameterSRI-FormatIndicator indicates a single WB SRI reporting, then a singleSRI is reported for the entire CSI reporting band (i.e., the reportedSRI is are WB).

In one embodiment Alt 8-2, if the higher layer parameterSRI-FormatIndicator indicates multiple WB SRIs reporting, then multipleSRIs are reported for the entire CSI reporting band (i.e., the reportedSRIs are WB).

In one embodiment Alt 8-3, if the higher layer parameterSRI-FormatIndicator indicates multiple SB CRIs reporting, then at leastone SRI is reported for each subband in the CSI reporting band (i.e.,the reported SRIs are SB). In one example, exactly one SRI is reportedfor each SB. In another example, multiple SRIs can be reported in oneSB. Also, the number of SRIs in each SB can be the same (hence is WB innature), and may determine the WB rank (TRI) value for UL transmission.Alternatively, the number of SRIs in each SB can changes from one SB toanother SB (hence is SB in nature), and may determine the SB rank (TRI)value for UL transmission.

Note that at least one of these alternatives (e.g. the aforementionedembodiments Alt 8-1 to Alt 8-3) is configured via higher layer signaling(RRC). For example, the signaling can be via the parameterSRI-FormatIndicator.

In a variation, the frequency granularity to report multiple SRIs isaccording to at least one of the following alternatives. In one exampleAlt 8-4, the frequency granularity is equal to the subband size. In oneexample Alt 8-5, the frequency granularity is smaller than the subbandsize, for example, equal to an RB. In one example Alt 8-6, the frequencygranularity is larger than the subband size, for example, a multiple ofsubband size. In one example Alt 8-7, the frequency granularity is afixed fraction (1/r) of the entire CSI reporting band, for example, ½ or¼ or ⅛. One of these alternatives is either fixed (e.g. theaforementioned embodiment Alt 8-4) or configured (e.g. via higher layerRRC signaling).

In one embodiment 8A, the reported SRI (or SRIs) indicates a SRSresource (or indicate SRS resources) associated with a small number ofSRS ports (e.g. 1 or 2). The UE is configured with N_(SRS)>1 SRSresources via higher layer signaling. Note that when N_(SRS)=1, then SRIdoes not need to be reported. In one method, N_(SRS)>1 when the UE isindicated with multiple SRIs. In another method, N_(CSI-RS)≥1 when theUE is indicated with multiple SRIs. One of the two methods may besupported in the specification.

In one embodiment 8B, the reported SRI (or SRIs) determines a rank value(TRI) that is equal to the sum of number of ports associated with theSRS resources indicated by the reported SRIs. Note that there is no needfor TRI indication since TRI is indicated implicitly via the indicationof multiple SRIs.

In one embodiment 8C, the number of ports associated with each of theN_(SRS) SRS resources is according to at least one of the followingalternatives. In one embodiment Alt 8C-1, the number of ports is thesame for all N_(SRS) resources. Therefore, the reported SRI (or SRIs)corresponds to a fixed rank (TRI) that does not change across SBs, i.e.,rank value is WB. In one embodiment Alt 8C-2, the number of ports can bedifferent from one resource to another. Therefore, if multiple SRIs arereported, then the rank (TRI) assumption can change from SB to another.For example, TRI in one SB can correspond to rank 1 (if thecorresponding reported SRI indicates a 1-port resource) and TRI inanother SB can correspond to rank 2 (if the corresponding reported SRIindicates a 2-port resource).

One use case of multiple SRI reporting is the case in which theprecoding or beamforming of UL data is in at least one of two domains(1) radio frequency (RF) or analog domain and (2) digital or basebanddomain. The N_(SRS) SRS resources can be beamformed using N_(SRS)beamforming vectors. These beamforming vectors can be obtained by the UEby measuring DL RS (e.g. CSI-RS) transmitted by the gNB (relying onUL-DL reciprocity). An example of such a system is high frequency (suchas millimeter wave) system.

Another use case is hybrid CSI in which the gNB indicates the followingtwo UL-related CSI reports (e.g. in DCI). In one example, the firstUL-related CSI report includes a long term and WB UL CSI indicating theinformation about a subspace or a set of candidate beamforming vectors.An example of subspace reporting is ii only reporting which indicates aset of DFT beams. In one example, the second CSI includes the SRI(s) asprovided in this embodiment (embodiment 8). The SRS resources for thissecond UL-related CSI reporting are beamformed or precoded using thesubspace or the set of candidate beamforming vectors reported in thefirst CSI report.

A few advantages/benefits of multiple SRI reporting (using beamformedSRS) over multiple TPMI reporting (using non-precoded or non-beamformedSRS and TPMI UL codebook) are as follows. In one example, the firstadvantage is in terms of performance gain wherein multiple SRI reportingis expected to show performance gain over multiple TPMI reporting. Thisis because of the fact that beamformed SRS can achieve more SINR at thegNB when compared with non-precoded SRS. In one example, the secondadvantage is that any beamforming or precoding vector can be used tobeamform the SRS resources. In particular, reliance on a codebook suchas TPMI UL codebook to beamform these resources is not necessary. In oneexample, the third advantage is that multiple SRIs can reduce DCIoverhead (bits) when compared with the overhead of indicating multipleTPMIs in DCI.

In one embodiment 9, the RI reporting alternatives in embodiment 2 isextended (applicable) to report TRI indication (e.g. via DCI signaling)either implicitly (e.g. via a joint filed for SRI and TRI in DCI) orexplicitly (e.g. via a separate field in DCI).

In one embodiment 10, which is a variation of the aforementionedembodiments 8 and 9, each SRS resource is configured/associated with afixed number (N) of ports. For example, N=1 or 2. Hence, the reportedSRI corresponds to a rank value (TRI) which is a multiple of N, i.e. therank values belong to {N, 2N, 3N, . . . }. The rank value (TRI) may ormay not reported. If TRI is reported, then the TRI is reported accordingto one of the examples in the aforementioned embodiment 9. Two examplesare as follows. In one example Ex 10-1: N=1 and the possible number oflayers (or rank values, TRI) belong to {1, 2, . . . }. In one example Ex10-2: N=2 and the possible number of layers (or rank values, TRI) belongto {2, 4, . . . }.

In one embodiment 11, when the UE is indicated with multiple SRIs (e.g.via DCI), then the UE is indicated with multiple CRIs as explained inthe aforementioned embodiments 8 to 10 of the present disclosure exceptthat the indicated SRIs has a dual-stage structure comprising twocomponents. In one example of WB SRI component, a single SRI indicatinga group or subset of SRS resources is reported for the entire CSIreporting band. In one example of SB SRI component: one SRI is reportedfor each subband in the CSI reporting band, where the reported SRIindicates a SRS resource in the group or subset of SRS resourcesindicated by the WB SRI component.

This is similar to the dual-stage W1W2 PMI codebook to report a WB PMI(i1) and multiple SB PMIs (i2).

In one embodiment, a dual-stage SRI is indicated only when the number ofports in each SRS resource is large than a fixed value, e.g. 2 or 4. Inanother method, whether to indicate one SRI (single-stage) or dual-stageSRI is indicated to the UE (e.g. via higher layer RRC signaling).

In one example 11-1, the UE is configured with K_(s)>1 sets of SRSresources, and the UE is indicated with a WB CRI to indicate (select)one SRS resource set (s) out of K_(s) SRS resource sets, and is alsoindicated with one SRI for each SB to indicate (select) one SRS resourceout of N_(SRS,s) SRS resources in the reported SRS resource set (s).

In one example 11-2, the UE is configured with K_(s)=1 set of SRSresources which are grouped (e.g. fixed grouping or sequentiallygrouping) into T groups. The UE is indicated with a WB SRI to indicate(select) one SRS resource group (t) out of T SRS resource groups in theconfigured resource set, and is also indicated with one SRI for each SBto indicate (select) one SRS resource out of N_(SRS,t) SRS resources inthe reported SRS resource group (t).

In one embodiment 12, a UE is configured (e.g. via RRC) to measure a DLresource set comprising N_(RS)>1 DL resources for DL CSIacquisition/reporting. The UE is further configured (e.g. via RRC) toreport a single or multiple DL resource indicator (DRI or DRIs)indicating one or multiple of the DL resources in the configured DLresource set. An example of DL RS is CSI-RS in which case DRIcorresponds to CRI.

In one embodiment 12A, a UE is configured (e.g. via RRC) to measuremultiple DL resource sets, each comprising N_(RS)>1 DL resources for DLCSI acquisition/reporting. The UE is further configured (e.g. via RRC)to report a single or multiple DL resource indicator (DRI or DRIs)indicating one or multiple of the DL resources in the configured DLresource sets. An example of DL RS is CSI-RS in which case DRIcorresponds to CRI.

In one embodiment 13, a UE is configured (e.g. via RRC) to transmit a ULresource set comprising N_(RS)>1 UL resources for UL CSI acquisition.The UE is then indicated with (e.g. via DCI) a single or multiple ULresource indicator (URI or URIs) indicating one or multiple of the ULresources in the configured UL resource set. An example of UL RS is SRSin which case URI corresponds to URI.

In one embodiment 13A, a UE is configured (e.g. via RRC) to transmitmultiple UL resource sets, each comprising N_(RS)>1 UL resources for ULCSI acquisition. The UE is then indicated with (e.g. via DCI) a singleor multiple UL resource indicator (URI or URIs) indicating one ormultiple of the UL resources in the configured UL resource sets. Anexample of UL RS is SRS in which case URI corresponds to URI.

FIG. 12 illustrates a flowchart of a method 1200 for CSI acquisitionaccording to embodiments of the present disclosure, as may be performedby a user equipment (UE). The embodiment of the method 1200 illustratedin FIG. 12 is for illustration only. FIG. 12 does not limit the scope ofthis disclosure to any particular implementation.

As illustrated in FIG. 12, the method 1200 begins at step 1202. In step1204, a UE (e.g., 111-116 as illustrated in FIG. 1) receives, from atleast one transmission and reception point (TRP) of a group of (N) TRPs,channel status information (CSI) configuration information.

In step 1206, the UE determines a CSI report based on the CSIconfiguration information. In this step, the determined CSI reportincludes a TRP indicator for selecting (M) TRPs of the group of (N)TRPs. In one embodiment, the CSI report further includes CSI for each ofthe selected (M) TRPs. In such embodiment N is greater than one, andwherein M is greater or equal to 1, and less or equal to N.

In one embodiment, the CSI report further includes a number (M) ofselected TRPs for CSI reporting. In one embodiment, the CSIconfiguration information includes a number (M) of selected TRPs for CSIreporting.

In one embodiment, the CSI report is partitioned into CSI1 comprisingCSI for N1 TRPs and CSI2 comprising CSI for N2 TRPs.

In one embodiment, the CSI report is transmitted via an uplink controlinformation (UCI) comprising two parts of UCI1 and UCI2. In suchembodiment, N1 is a fixed number greater or equals to one regardless ofa value of M, N2 is greater or equals to zero, and equals to M-N1.

In one embodiment, the UCI1 includes the CSI1 and a UCI indicator forindicating a number of information bits for the UCI2, and the payload ofUCI1 transmission in terms of number of information bits is fixed andthe UCI2, and the payload of UCI2 transmission in terms of number ofinformation bits is variable.

In one embodiment, the UCI indicator for indicating the number ofinformation bits of the UCI2 comprises a bitmap b₁b₂. . . b_(N) oflength N. In such embodiment, the bitmap comprises M ones and N-M zeros.In such embodiment, CSI for an i-th TRP is not included in thedetermined CSI report when a b_(i) is set to zero and CSI for an i-thTRP is included in the determined CSI report when a b_(i) is set to one.

In one embodiment, the UE measures N sets of CSI-reference signal(CSI-RS) resources, one set for each of the group of (N) TRPs.

In one embodiment, the UE determines based on the CSI configurationinformation, the CSI report including a CSI-RS resource indicator (CRI)that indicates M of the N sets of CSI-RS resources, and CSI for each ofthe M CSI-RS resources.

In one embodiment, the CRI comprises N components, CRI₁, CRI₂, . . . ,and CRI_(N), M of which are greater than zero and remaining N-M arezero. In such embodiment, CSI for an i-th set of CSI-RS resources is notincluded in the determined CSI report when CRI_(i) is set to zero; andCSI for an i-th set of CSI-RS resources is included in the determinedCSI report when CRI_(i) is greater than zero, and the CSI comprises atleast one of channel quality indicator (CQI), a rank indicator (RI), aprecoding matrix indicator (PMI), or a layer indicator (LI).

In step 1208, the UE identifies, based on the configuration information,one or more TRPs of the group of (N) TRPs to transmit the determined CSIreport.

In step 1210, the UE transmits, to the one or more TRPs, the determinedCSI report over an uplink channel.

In one embodiment, the UE in step 1210 further transmits, to the one ormore selected TRPs, the determined CSI report including the CRI and theCSI for each of the M CSI-RS resources.

FIG. 13 illustrates a flowchart of another method 1300 for CSIacquisition according to embodiments of the present disclosure, as maybe performed by a transmission/reception point (TRP). The embodiment ofthe method 1300 illustrated in FIG. 13 is for illustration only. FIG. 13does not limit the scope of this disclosure to any particularimplementation.

As illustrated in FIG. 13, the method 1300 begins at step 1302. In step1304, a TRP (e.g., 101-103 as illustrated in FIG. 1) transmits, a userequipment (UE), channel status information (CSI) configurationinformation, wherein the TRP is at least one TRP of a group of (N) TRPs.

In step 1304, the CSI configuration information includes a number (M) ofselected TRPs for CSI reporting.

In step 1306, the TRP receives, from the UE, a CSI report over an uplinkchannel. In step 1306, the CSI report is determined based on the CSIconfiguration information. In one embodiment, the CSI report includes aTRP indicator for selecting (M) TRPs of the group of (N) TRPs, and CSIfor each of the selected (M) TRPs. In such embodiment, N is greater thanone, and M is greater or equal to 1, and less or equal to N.

In one embodiment, the CSI report further includes a number (M) ofselected TRPs for CSI reporting.

In one embodiment, the CSI report is partitioned into CSI1 comprisingCSI for N1 TRPs and CSI2 comprising CSI for N2 TRPs.

In one embodiment, the CSI report is transmitted via an uplink controlinformation (UCI) comprising two parts of UCI1 and UCI2. In suchembodiments, N1 is a fixed number greater or equals to one regardless ofa value of M and N2 is greater or equals to zero, and 1 equals to M-N1.In such embodiment, the UCI1 includes the CSI1 and a UCI indicator forindicating a number of information bits for the UCI2, and the payload ofUCI1 transmission in terms of number of information bits is fixed. Insuch embodiment, the UCI2 includes the CSI2 and the payload of UCI2transmission in terms of number of information bits is variable.

In one embodiment, the UCI indicator for indicating the number ofinformation bits of the UCI2 comprises a bitmap b₁b₂ . . . b_(N) oflength N. In such embodiment, the bitmap comprises M ones and N-M zeros.

In one embodiment, CSI for an i-th TRP is not included in the determinedCSI report when a b_(i) is set to zero.

In one embodiment, CSI for an i-th TRP is included in the determined CSIreport when a b_(i) is set to one.

In step 1306, the TRP further receives, from the UE, the determined CSIreport including a CSI-RS resource indicator (CRI) and the CSI for eachof M CSI-RS resources.

In one embodiment, the CSI report includes the CRT that indicates M ofthe N sets of CSI-RS resources, and CSI for each of the M CSI-RSresources. In such embodiment, the N sets of the CRT resources ismeasured, by the UE, one set for each of the group of (N) TRPs.

In one embodiment, the CRT comprises N components, CRI₁, CRI₂, . . . ,and CRI_(N), M of which are greater than zero and remaining N-M arezero. In such embodiment, CSI for an i-th set of CSI-RS resources is notincluded in the determined CSI report when CRT, is set to zero, and CSIfor an i-th set of CSI-RS resources is included in the determined CSIreport when CRL is greater than zero. In such embodiment, the CSIcomprises at least one of channel quality indicator (CQI), a rankindicator (RI), a precoding matrix indicator (PMI), or a layer indicator(LI).

Although the present disclosure has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

None of the description in this application should be read as implyingthat any particular element, step, or function is an essential elementthat must be included in the claims scope. The scope of patented subjectmatter is defined only by the claims. Moreover, none of the claims areintended to invoke 35 U.S.C. § 112(f) unless the exact words “means for”are followed by a participle.

1. A user equipment (UE) in a communication system, the UE comprising: atransceiver configured to: receive, from a base station, configurationinformation for a plurality of sounding reference signal (SRS) resourcesets, wherein each SRS resource set is associated with one or more SRSresources; receive, from the base station, downlink control information(DCI) including (i) an SRS resource indicator field and (ii) an SRSresource set indicator field indicating an SRS resource set associatedwith an SRS resource indicated by the SRS resource indicator field; andtransmit, to the base station, an uplink transmission based on the SRSresource indicator field.
 2. The UE of claim 1, wherein: the DCIincludes multiple SRS resource indicator fields, and the uplinktransmission is transmitted based on the multiple SRS resource indicatorfields.
 3. The UE of claim 1, wherein one SRS port is configured foreach SRS resource.
 4. The UE of claim 1, wherein the plurality of SRSresource sets is configured for a non-codebook based transmission.
 5. Abase station in a communication system, the base station comprising: atransceiver configured to: transmit, to a user equipment (UE),configuration information for a plurality of sounding reference signal(SRS) resource sets, wherein each SRS resource set is associated withone or more SRS resources; transmit, to the UE, downlink controlinformation (DCI) including (i) an SRS resource indicator field and (ii)an SRS resource set indicator field indicating an SRS resource setassociated with an SRS resource indicated by the SRS resource indicatorfield; and receive, from the UE, an uplink transmission based on the SRSresource indicator field.
 6. The base station of claim 5, wherein: theDCI includes multiple SRS resource indicator fields, and the uplinktransmission is received based on the multiple SRS resource indicatorfields.
 7. The base station of claim 5, wherein one SRS port isconfigured for each SRS resource.
 8. The base station of claim 5,wherein the plurality of SRS resource sets is configured for anon-codebook based transmission.
 9. A method performed by a userequipment (UE) in a communication system, the method comprising:receiving, from a base station, configuration information for aplurality of sounding reference signal (SRS) resource sets, wherein eachSRS resource set is associated with one or more SRS resources;receiving, from the base station, downlink control information (DCI)including (i) an SRS resource indicator field and (ii) an SRS resourceset indicator field indicating an SRS resource set associated with anSRS resource indicated by the SRS resource indicator field; andtransmitting, to the base station, an uplink transmission based on theSRS resource indicator field.
 10. The method of claim 9, wherein: theDCI includes multiple SRS resource indicator fields, and the uplinktransmission is transmitted based on the multiple SRS resource indicatorfields.
 11. The method of claim 9, wherein one SRS port is configuredfor each SRS resource.
 12. The method of claim 9, wherein the pluralityof SRS resource sets is configured for a non-codebook basedtransmission.
 13. A method performed by base station in a communicationsystem, the method comprising: transmitting, to a user equipment (UE),configuration information for a plurality of sounding reference signal(SRS) resource sets, wherein each SRS resource set is associated withone or more SRS resources; transmitting, to the UE, downlink controlinformation (DCI) including (i) an SRS resource indicator field and (ii)an SRS resource set indicator field indicating an SRS resource setassociated with an SRS resource indicated by the SRS resource indicatorfield; and receiving, from the UE, an uplink transmission based on theSRS resource indicator field.
 14. The method of claim 13, wherein: theDCI includes multiple SRS resource indicator fields, and the uplinktransmission is received based on the multiple SRS resource indicatorfields.
 15. The method of claim 13, wherein one SRS port is configuredfor each SRS resource.
 16. The method of claim 13, wherein the pluralityof SRS resource sets is configured for a non-codebook basedtransmission.